William Wynne

"The Corvair Authority"
5000-18 HWY 17 #247
Orange Park, FL 32003


2003 Ask The Authority!

NOTE: An important tip we learned at Corvair College #4 during Sun 'N Fun 2003 from new Contact! magazine editor Pat Panzera, and also airboat enthusiast Greg Lowe of Miami who started shopping for an airplane to build for his Corvair motor at Sun 'N Fun:
To search for anything on any of these Web pages, the toolbar on the top of your browser has an Edit function with a Find on this Page feature. Just type in the key word in which you're interested, and the Find feature will take you right to it. If you don't see your question answered here, then by all means e-mail William at WilliamTCA@aol.com. Thank you.

Subj: Hiatus
Date: 12/31/03

Thank you all for tuning in to the Daily Question and Answer Page. We've put this page on hiatus while we concentrate on completion of the Zenair 601. Those of you who subscribe to The Corvair Flyer will be receiving an update shortly. We'll also post any big news at The www.FlyCorvair.com News page. We hope to see you all soon. Of course, we're still answering an average of 20 private e-mails a day. It can just be done a lot faster without editing for page posting. Happy building and flying.

Subj: Gary Coppen's Skycoupe
Date: 12/30/03

Do you know what the typical cylinder head and oil temperatures are on Gary Coppen's Skycoupe? The pictures on your Web site of this particular engine installation are remarkable for their lack of clutter on top of the cylinders which, I imagine, makes for a good down-flow of cooling air. Where is the oil cooler in this installation? Regards,

Paul Madden, pmadden@draper.com
Reply from WW:
This engine is typical of Corvairs converted according to my Conversion Manual. It runs 320F in cruise, up to 400F in sustained climbs. The oil temperature is 210 in cruise, peaks about 230F. The front starter arrangement allows for a completely stock oil system, including the stock cooler, which is on the right rear corner of the motor when viewed from the propeller. Thank you for the kind compliments on the installation. I did it in my shop. I strive for simplicity, and neat appearance.

Subj: Engine disassembly - defeating frozen studs Ways & Means?
Date: 12/29/03

Is there any better way to tackle disassembling these backyard gems that have waited just a little too long to see a wrench that cares, now twisting on frozen studs?...

Your Web site and Corvair knowledge are a treasure... With much appreciation,

Steve Kiblinger, SKiblinger@cs.com
Reply from WW:
One product that works exceptionally well is Kroil. It's available from Aircraft Spruce. Try tightening the stud a minute amount first. You can always heat the nuts with a propane torch, and wick in birthday candle wax. Capillary action will pull it inside and make it easier to unscrew.

Subj: 601 Install Kit?
Date: 12/28/03

Another e-mail just to say thanks. And to let you know that I, for one, am hoping that you might consider a kit type of install for those of us who are ignorant of a lot of the engine matching of carbs, manifolds, where to install manifold pressure gauge, CHT, EGT, etc., etc., or perhaps a specific sheet with that info for those of us going the Corvair/601 route: a basic here's the exhaust, here's the intake manifold, the alternator bracket and the alternator package, or at least a parts list and drawings. I don't mean to presume on your good nature. I am sure there is a way that you can be compensated, at least I would be willing, since all of this stuff is new and I need guidance. Without you, I would not even consider this type of project, so, again, thanks. All my best,

Jim Dankovich, Zenair 601, Troy, Mich., jdankochiro@yahoo.com
Reply from WW:
I will be using an MA3-SPA carb on our 601. I think it is the best way to go. An Aerocarb would work also, but I am partial to float carbs. I will outline the whole 601 fuel system on our 601 Corvair Flyer Web page when we get it done, in case you want to follow along.

Subj: Oil Pan and top cover thickness
Date: 12/27/03

Do the Oil Pan and the Top Cover contribute significant strength to the engine case? Is there a minimum thickness you would recommend? How thick are your pan and top cover? Thanks,

Bill Wright, william_wright@wlbeng.com
Reply from WW:
The Oil Pan and Top Cover do not contribute to the strength of the case. The thickness is based on two things: The Top Cover needs to be .125" thick. Less than this will not effectively keep the gasket in place when a front mount starter is used. You could get away slightly thinner with a rear starter, but real thin pieces distort under the bolt heads and are prone to leak. On the Oil Pan, the rail is made of .125" and the box which forms the sump is .050". I consider this the minimum thickness desirable. You might go thinner if you used area washers under the heads of the bolts, but you would lose some of your weight advantage with the additional hardware. An oil leak at the pan level is serious business; it will make a big mess, and potentially drain most of the oil from the engine. I have flown this stuff a lot. The cover and pan are really part of the oil system, and not the place to be looking to save weight on the motor. We have gotten the stuff down to what I think is the minimum most people should consider.

Subj: Pitts Powered Corvair
Date: 12/26/03

Have you had any experience with Corvairs in Pitts Specials? I am building a Pitts S1C, and the early Pitts used 100 to 120hp engines (O-235 or O-290 Lyc.). Sunny Sunday morning flying will be the main use. Aerobatics are not intended at this stage. I am trying to build down to the weight of the early Pitts (later ones using 180hp to 200hp are up to 50% heavier) and the weight of the Corvair engine is particularly attractive for achieving this goal. I would appreciate your comments. Regards,

Dennis Emms, demms@bigpond.com
Reply from WW:
An early flat wing Pitts would fly with a Corvair. You are very right that most of them are too heavy. A friend of mine built an S1S, IO-360, metal prop, electric start (no alternator), aluminum geared, and it weighed an honest 808 pounds painted. Most planes never get near this. A very light S1C, built with this same philosophy, could be Corvair powered. I have a lot of respect for the designs of CP. They are strong, reasonably simple, and good flyers.

Subj: RB Engine, Zenair
Date: 12/24/03

Holiday greetings to you and yours! I just bought your book, but I'm visiting relatives in Ohio and I don't have it with me. Thanks for getting back to me so soon. Should I assume that your endorsement of the '65 Corsa engine cases for an airplane means they will be compatible with an 8409 crank, 10-10 cam, and other conversion components? By the way, I hope to purchase the Zodiac 601 kit, maybe by summertime. Did I understand correctly that you were able to buy major components such as the fuselage and wings pre-fabbed by the factory? Thanks. Next trip I'll bring the book - ya never know!

Doug Jamison, jamahaus@yahoo.com
Reply from WW:
RBs are true 1965-66 Corsa engines. Their bottom ends make good airplane motors. They do not have the 140-auto trans timing gear issue, because no Corsa ever had an auto trans. If available at a good price, buy them. An RB has an 8409 crank, and all Corvair motors can have an OT-10 cam installed. All of my conversion parts can be fitted to any model of the motor.

Our plane was slightly more prefabricated than the standard kit. It was the factory demonstration piece at Oshkosh. The kit is inexpensive to ship because it can be put in flat packages. No 51% kit can come with parts like wings finished. Ours were in kit form, and they have proven to be very easy to build.

Subj: Alternator
Date: 12/23/03

I have ordered your Front Starter Kit and Alternator Pulley from the Online Catalog today. I have made up my mind to do it the right way and make this Piet an electric start. The only question I have is, will the small alternator bracket in the Manual work with the starter kit I've ordered? Merry Christmas and a Prosperous New Year,

Gary Bell, Manual 5151, Pietenpol, Delaware, Ohio, glbell@midohio.net
Reply from WW:
Thank you for your order. The alternator bracket in the Manual is designed to work with a Kubota 14amp alternator. Today, most people are using the John Deere 18amp model which is slightly larger. We'll have the new drawings for this mount available shortly after the first of the year. Both are compatible with the Front Starter Kit, but I'd suggest you go with our new model. We're out of town right now, and we'll ship your Starter Kit when we get back after the New Year.

Subj: Corvair in CH701
Date: 12/22/03

Can the Corvair be used in the Zenair CH701?

elewis12@shaw.ca
Reply from WW:
The Heintz family tells me that the 701 was engineered for lighter motors. Although they have flown with engines like the O-200, which are in the same weight category as the Corvair, the family feels that 701 builders should really stay with lighter motors.

Subj: Cassutt and Corvair
Date: 12/21/03

How would a Cassutt do with a Corvair?

dunrite@phango.com
Reply from WW:
I have done two installations of Corvairs into Cassutts, and they fit fairly well. The motor is shorter and narrower than an O-200. For reasons to do with people (marriage, money, etc.), not machinery, these two builders are on a very slow pace. Overall it is a good match, as long as you are not interested in hard acro work, as you said. Write me with any questions you may have.

Subj: Dutch Corvair Engine
Date: 12/20/03

I am going to build a KR2S and did some reading into suitable engines. I have read a lot about builders with Corvair engines and they are very happy with them. So I have a great interest in getting one myself. That is why I mail you. Every article I read shows me back to your Web site. It really looks like you know these engines.

I live in the Netherlands and I do not know of any Covair engines for sale. My question to you is if I would like to get one of these engines, is it possible to do it true to you? What would you suggest is the best thing for me to do? What engine do you think is the most suitable for the KR2S? Can you just give me a general idea of possibilities or if it is not possible let me know. If it is possible, at what cost will I be looking at if you would build an engine for me?

It is not that I am ready for an engine now, but I would really like to know what I can or can't do. Excuse my English but this is not my strongest point. Greetings,

Peter Waijenberg, KR2S, Netherlands
Reply from WW:
Your English is 1,000 times better than my Dutch. Your e-mail was very clear. We've exported engines all over the world. We can send you a rebuildable core or a completely overhauled engine. Crating and shipping on either motor is about $500 to Europe. Rebuildable core motors start at $299. A completely overhauled and test run engine with electric start and ignition system but no carburetor or exhaust is about $6,000. The cost in parts to overhaul and convert the motor yourself is about $3,000.

Everyone starts with one of my Conversion Manuals. You can order one from my Web site at The www.FlyCorvair.com Online Catalog, or you can mail us a money order for $74USDollars payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129 USA.

The Manual contains a lot of information on fuel systems, and other topics related to the airframe and preparing it for the engine installation. I also sell motor mounts for the KR. It is a great match.

Let us know how we can help you with your airplane building plans.

Subj: Corvair in Murphy Rebel
Date: 12/19/03

Would you know of anyone using the Corvair engine on a Murphy Rebel Kit aircraft? Just curious. Great Web page!

R. Wayne Moore, MOORERW@cpchem.com
Reply from WW:
We have had a number of guys talk about it, but I don't think one has flown yet. It is a very nice plane, and I distinctly remember being impressed with it the first time I saw one in person 10 years ago. I am sure that a Corvair could power one nicely.

Subj: Corvair in Vans RV-9
Date: 12/18/03

You have stated that the Corvair engine is not a good engine for the Vans line of aircraft. You also state that the Corvair may be used to replace the O-235 Lycoming. The RV-9 and RV-9A can use the O-235 Lycoming engine. My question is, can the 190cid Corvair engine be used on the Vans RV-9 aircraft? And does your Manual cover turboing the 190cid Corvair engine?

Harold G. Mothersill, lmothersil@aol.com
P.S. Love the information on your Web site. It may make it affordable for me to build and fly my own aircraft.
Reply from WW:
The RV-9 is certainly a fine aircraft, and I saw the picture in Sport Aviation of the one flying on a 100hp O-235. But I did note that the second one the factory built had an O-320. Most of the ones I've seen in the field also have O-320s.

While a large displacement Corvair can do the work of an O-235 in some airframes, particularly ones where propeller diameter is restricted, and there's an opportunity to use the Corvair's higher rpm potential, it is not a direct replacement for an O-235 in all situations. Additionally, a 190cid Corvair motor is potentially 50 pounds lighter than an average O-235, and may actually present a weight and balance issue on an aircraft like an RV-9.

If you've not made up your mind which metal airplane you like, but the economy of the Corvair motor appeals to you, I would suggest checking out Zenair's 601. While the airframe kits are roughly the same cost, the 601 is vastly easier to build, a lighter plane, and with a lower horsepower requirement, is a perfect match for the Corvair motor. You can check our progress on our own 601 at The www.FlyCorvair.com 601 Web page.

Subj: Corvair in Gyrocopter
Date: 12/17/03

I had the pleasure of talking to you during Sun 'N Fun, and with all the questions I asked you about Corvair engines, I forgot to ask the most important one: Can a Corvair engine be used on a Gyrocopter? I currently have a Benson Gyrocopter with a MAC engine and would like to replace it with something more reliable and easier to start. Thank you for your help.

Phil Tua, ptua@airtranairways.com
Reply from WW:
The Corvair engine has been used in Benson style gyros since 1967. However, it has not been a common installation like the MAC or other engines. The Corvair's double sided thrust bearing allows it to be used as a pusher. It is capable of developing substantial power, especially when used with a smaller diameter prop, like a gyro.

Subj: Corvair acquisition success
Date: 12/16/03

Your advice about finding an engine was a big help. I believe I've found an engine within 100 miles of me. Would it be prudent for me to get 2 of these engines (just in case!)? Thanks again for the great WEB site!

George Nelson (US Army, Retired), Magazine, Ark., smokie@arkansas.net
Reply from WW:
Many of our customers report finding an engine for $100, with a second one available for $50 or so. If offered a deal like this, I'd take the second one also. Corvairs have very good parts interchangeability, and a second core engine is good for mocking up engine mounts and cowlings.

Subj: Moveable Corvair College
Date: 12/15/03

My name is Tim Hendrix and I live in Rockport, IN. I am considering building a Pietenpol AirCamper and powering it with a Corvair engine. Is there any Corvair engine that is not well suited for conversion? I don't know a lot about them yet, so I thought I would ask. I have yet to locate an engine locally, but I am still looking. I just wanted to ask so when I do find one, I won't be getting something I can't use.

I have enjoyed your Web site and look forward to purchasing your Conversion Manual soon. Do you have a schedule for upcoming Corvair College dates and do you ever hold any close to Southern Indiana? Thanks for any info. Sincerely,

Tim Hendrix, Rockport, Ind., timandnanh@psci.net
Reply from WW:
The engine you're looking for is a 1964-69. Early motors are only 145cid and are not worth pursuing. The Conversion Manaul contains all this information in great detail.

We are contemplating another Corvair College in the middle of 2004 in the central U.S., but have not firmed up the date yet. We'll post the latest on Colleges at The FlyCorvair.com News Page.

Subj: Engine
Date: 12/14/03

I received the Corvair Conversion Manual and immediately read through it twice. Then I began a search for an engine core, using the resources suggested. I called all the wrecking yards here in Alaska, and they only laughed at me. I finally found only one Corvair with engine, but not for sale. I began scouting along all the back roads looking in yards, but with no success. So I then began searching the Internet, as well as wrecking yards on the West Coast. I did locate two engines in Vancouver, WA, with a cost of nearly $1,000 for cores, including transportation to me. As one final desperate attempt to find something closer, I ran an ad in the local paper. Wouldn't you know it - a gentleman called up who lives not more than 20 miles from me with just what I needed. It's just as you said, probably one is closer than you think. You just have to look. Thanks for the encouragement to start this interesting project.

Wendell Downs, Alaska, downswl@mtaonline.net
Reply from WW:
When you fly your Corvair powered plane to Oshkosh, I'm going to put you on the stage in The Theater in The Woods so you can tell this story to everybody. I've said it a million times, but the story of your engine search is certainly one of the better ones. It goes a long way to show how common Corvair engines really are. Thank you for sharing.

Subj: Bushcaddy L120
Date: 12/13/03

The Bushcaddy L120 would seem an ideal candidate for a 100-110 HP Corvair engine since the parent company, CLASS, recommends an O-200 for this service. Regards,

Moe Baxter, myb8@sympatico.ca
Reply from WW:
I've not seen a Bushcaddy in person. But a number of our customers have, and say they're very impressed with it. We have five or six Corvair guys who are either working on this plane as their airframe, or have said it is in the planning stages for them. The Bushcaddy Web site indicates 220 pounds as a maximum engine weight, but also lists a Lycoming O-235, which is 40 pounds heavier than this, as an engine option. Standard Corvair motors are fairly close to the 220 mark, and would probably power this aircraft nicely.

Subj: Vans RV-9
Date: 12/12/03

You have stated that the Corvair engine is not a good engine for the Vans line of aircraft. You also state that the Corvair may be used to replace the O-235 Lycoming. The RV-9 and RV-9A can use the O-235 Lycoming engine. My question is, can the 190cid Corvair engine be used on the Vans RV-9 aircraft? And does your Manual cover turboing the 190cid Corvair engine?

Harold G. Mothersill, lmothersil@aol.com

P.S. Love the information on your Web site. It may make it affordable for me to build and fly my own aircraft.

Reply from WW:
The RV-9 is certainly a fine aircraft, and I saw the picture in Sport Aviation of the one flying on a 100hp O-235. But I did note that the second one the factory built had an O-320. Most of the ones I've seen in the field also have O-320s.

While a large displacement Corvair can do the work of an O-235 in some airframes, particularly ones where propeller diameter is restricted, and there's an opportunity to use the Corvair's higher rpm potential, it is not a direct replacement for an O-235 in all situations. Additionally, a 190cid Corvair motor is potentially 50 pounds lighter than an average O-235, and may actually present a weight and balance issue on an aircraft like an RV-9.

If you've not made up your mind which metal airplane you like, but the economy of the Corvair motor appeals to you, I would suggest checking out Zenair's 601. While the airframe kits are roughly the same cost, the 601 is vastly easier to build, is a lighter plane, and with a lower horsepower requirement, is a perfect match for the Corvair motor. You can check our progress on our own 601 at The www.FlyCorvair.com 601 Web page.

Subj: Corvair Horsepower
Date: 12/11/03

How many HP can the Corvair engine produce?

Duane Davis, Universal City, Texas, Tankboot@HotMail.Com
Reply from WW:
The Corvair motor can reliably produce 100-125hp as a direct drive powerplant. This depends on what displacement you use. Additionally, I'm working on turbo versions of the engine, which have the potential to increase this by 15-20% and retain this level of power to 10,000 feet. The Corvair motor is a very strong design. Engines built for drag racing have recorded in excess of 450 rear wheel horsepower on stock crankshafts and engine cases. Engines with stock connecting rods have exceeded 350hp. While these are short durations, it is an indication of how we have de-rated the engine to obtain reliability. The Corvair is the only automotive engine I can think of where we actually ask less hp of the engine than the automotive use was rated at.

Subj: Canadian Corvair Pietenpol
Date: 12/10/03

I have been going over your Web page and find it very interesting to read. I am building a Pietenpol aircraft and have built the short fuselage with the intent to install a Model A Ford.

But I have changed my mind and I am very interested in the Corvair engine. Finding a block up here seems to be a hard thing to do. But here is what I want to know...can I build just a simple Plane-Jane engine? Nothing special, I just want to hand prop it! And have it not cost me an arm & leg, so to speak. I have an aviation parts business up here. You would think I could get cheap parts for an O-200 up here - not likely. The Corvair looks like the way to go. I just want it simple and reliable. Can you help to guide me in the right direction!

Bill Budgell, Pietenpol, Canada, wbudgell8965@rogers.com
Reply from WW:
Bernie Pietenpol was an aviation entrepreneur just like you, but still he chose the Corvair motor every time he built an airplane after 1965. I have to think he had access to a lot of 65 and 85 Continentals, but never used one. Our Pietenpol airplane was originally Ford powered for a few hours in the 1960s, but was then converted to Corvair power for the rest of its life. I like the sound of A motors, and they're fun. But there's just a lot more utility to be had out of a Corvair engine. Somewhere between 8-10% of our customers are from Canada, and for the most part, they've all been able to find good core motors to work with. A complete overhaul and conversion of a hand-prop motor has been done for less than $1,500. There simply is no other bargain quite like this in aviation. Our simple Front Start Systems are retrofittable to hand prop motors built from my Conversion Manual. They are not heavy, nor exceptionally expensive. I like them on a Piet because it is not the easiest plane to get in and out of, and being able to start it from the inside is nice. Let us know how we can help.

Subj: Engine Mount Delivery for 601XL
Date: 12/9/03

After reading through your Conversion Manual, I've decided to proceed with the Corvair for powering my 601XL. This leads me to ask about the approximate lead time and cost for the Engine Mount for the 601XL?

Thanks for writing a no nonsense, easy to read Manual.

Bill Cribb, Zenair 601XL, N601WC (reserved), wscribb@centurytel.net
Reply from WW:
We have several 601 Motor Mounts in the works right now. I intend to finish them in time for Christmas (we just moved into a brand new 4,000 square foot hangar and we're just getting the tools organized). I plan on working through Dec. 22 to get out every order.

I've built about half a dozen Mounts for 601s already. This tune up period allowed me to perfect the jigging, and come up with an accurate number for the time and materials involved, etc. Our price for 601 Motor Mounts is $589. This price includes all the polyurethane bushings to mount the motor, the actual AN hardware to mount the motor itself, including the nuts, washers and cotter pins. The Motor Mount is shipped unpainted. It has a light coating of oil, so it will not rust. The cost of shipping and handling varies with each address. Most of the mounts I've built over the years have gone out by FedEx ground. It is typically $40-$60 to ship one. They are very light, but they are subject to an oversize charge. Let us know whenever you're ready. You can simply send a check made payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or pay by credit card via the www.FlyCorvair.com Online Catalog.

Subj: Sport Pilot 601
Date: 12/8/03

I am very interested in your Zenair 601XL with Corvair engine. I am wondering if this airplane and engine combination would be a good candidate for the "Sport Pilot" category. Do you have any idea what the finished airplane's empty weight will be? The Corvair engine is a bit heavier than the Rotax 912 that Zenith is promoting as the best choice for Sport Pilot (because of its light weight). I'm wondering what the useful load will be using the proposed 1232 pound gross weight that the Sport Pilot proposal allows. Your thoughts are appreciated. Thanks,

Rob Fierberg, rfierb6707@hotmail.com
Reply from WW:
The XL model of the 601 was designed from the beginning for the proposed Sport Pilot category. As our aircraft is not complete, I cannot tell you exactly what the empty weight will be. The factory airplane has a full panel and a number of items which may make the airplane weigh a bit more than average. We're shooting to bring our airplane in at 732 and retain a 500 pound useful load in the category. Watch our www.FlyCorvair.com 601 Web page as we make further progress on this airplane.

Subj: Distributor Recurving
Date: 12/7/03

I have a distributor that would need re-building/curving. I live in Winnipeg, Canada. I will be in Miami, Florida, on May 1st next year and would like to pick up the rebuilt distributor there and avoid the shipping/handling/brokerage/tax/etc. charges. Questions: How much lead time do you need to re-build and test the distributor? Would I get the same one back or would you just store the one I send as a core? What kind of condition must it be in when I send it to you? What do I tell the security people at the airport when the distributor goes through the x-ray machine? Thanks. Clear Skies!

Martin Bima, STOL-Vair, Winnipeg, Canada, mbima@hydro.mb.ca
Reply from WW:
We're about 240 miles north of Miami. It is an easy four hour drive on the Interstate if you'd like to visit. I keep dual ignition distributors in stock. I can redo yours, but it's much easier if we exchange it. I can generally re-use something from every Corvair distributor we get. Even if it looks pretty grimy, send it. It doesn't need to have a cap, vacuum advance or points plate. We carry aircraft parts around the country all the time, and never have a problem with this. If you look at my safety shaft design, at first glance, it must look suspicious in an x-ray machine. Yet, we've had no problems traveling on airlines with these parts after they're inspected for a minute.

Subj: Corvair engine in Ercoupe
Date: 12/6/03

Have you ever heard of an Ercoupe with a Corvair engine? Is it possible? Feasible? I had a '67 Corvair convertible totally restored quite a few years ago. I'm looking at buying a two-place airplane and am not sure if I want to go with a homebuilt or not. In the non-homebuilt category, the Ercoupe is in my price range. Some I've seen are projects with no powerplant. Just wondering what would be involved in putting a Corvair powerplant in an Ercoupe.

Steve Roberts, Claymont, Del., dvcsteve@comcast.net
Reply from WW:
It is not easy to get FAA approval to put a non-certified motor on a certified airframe. If you pull it off, the airplane will have to be flown in a restricted flight category which likely will not allow passengers or flights outside your area. While a Corvair would certainly power an Ercoupe nicely, it would not provide you with a very useful aircraft. My best suggestion is continue looking for a homebuilt of your choice.

Subj: 'Vair Powered Piet Update
Date: 12/5/03

Hope all is well with you both. The (wood frame) Piet is going well. I decided to rehab the landing gear and wheels I bought from you after all. The cable/drum brakes are really just for run ups anyway. Got any idea where I can get replacement brake shoes? I'm real close to having the fuselage up on the gear. Also, I think we have taken care of the flywheel/starter issues after a good bit of "toothy" research (we have a love/hate relationship at NAPA now, just kidding...). Gonna lay a good one on you: We're looking into testing an updraft carb for the 'vair in just a bit. It's 35mm with a choke and standard float and made by Holly and they are fairly reasonable. Yup, leave it to a farm boy. The Ford 3000 gas tractor uses this carb and all indications are that it should work just fine. To start the break-in period though, we're going to mount the stock two carbs, synched, while I work out the tubing for intake system. I'm finishing out the rest of the "systems," i.e. charging, starter and monitoring instruments. Well, that's about it for now. Let me know if you guys get up this way. I'm going to do my best to catch Sun 'N Fun and look ya'll up! Till then,

Mike Denton, Pietenpol, Clarksville, Va., islanddocks@kerrlake.com
Reply from WW:
It's good to hear from you. When reading your e-mail, I thought about how long we've been hearing from you - four years to my memory, anyway.

The wheels were original equipment on J-3 Cubs. You can check Web sites that specialize in J-3 parts. I think Wag-Aero has J-3 parts. If not, Univair does.

Your carb ideas are good. I used to break in brand new engines on stock carbs just so they would start and run cleanly right off the bat. The engine's not finicky about carburetion, and as long as you don't tell the Chevrolet product it's sucking through a Ford item, it should work for you. Look for us at the Zenair booth at Sun 'N Fun. We'll see you then.

Subj: Corvair + Zenair 601
Date: 12/4/03

I ran into the link to your Web page and the Corvair engine installation - looks clean. I will be checking back to see how you optimize the installation and the performance.

Your article on carb ice is definitely food for thought. I've been mulling over the auto gas conversion to save money so I can afford to let my five kids learn to fly. But, the common sense in your article brought reality to that idea.

ronald_brooks@dot.state.ak.us
Reply from WW:
Thank you for the complimentary thoughts. Auto gas can definitely be used, but does require more attention to a number of issues. We have several pages of information on this in the Conversion Manual. A number of our customers fly on it and we've done a lot of testing. It works, but as I've said, requires more care in operation than AvGas.

Subj: Experimenter article
Date: 12/3/03

I just wanted to say I enjoyed the article in Experimenter last month. I guess there's still a few snake oil merchants out there, eh?

MRBarnard@webtv.net
Reply from WW:
Yes, there are, and I'm sure there always will be no shortage of snake oil manufacturers. But, by and large, the good outweighs the bad, and as long as all the builders are educated, the market will take care of itself.

For those of you who don't subscribe to the premier magazine for homebuilders, I can't recommend highly enough visiting the EAA Web site and adding the publication to your membership.

Subj: Alabama Core Motor
Date: 12/2/03

I know that you're busy and this is probably one of the most frequently asked questions that you get, however, I am having real difficulty finding a core engine to get started. At this stage on the construction of my Zenith 601XL and given my current building pace, I don't have to resolve engine questions just yet, but I would like to go in that direction.

Originally, I was looking for a Lycoming core to rebuild because I have some limited experience with the engine type from a previous probject. I had also previously purchased your original conversion manual and, later, the upgraded version (Manual #5289) when I was still considering building a KR. It was only when I recently visited the Zenith Web site and noticed the reference to your Zenith project that I began considering the Corvair installation for this aircraft.

As a part of this process, I re-read your Conversion Manual in detail and have also reviewed the shop manual and some other publications. I also reviewed some of the parts sources (Clarks, etc.) to see what's available for the engine. To date, however, the only problem which has developed occurred when I began to search for a good core engine to continue the process. I've talked to a local Corvair group, looked through the Internet, and have searched through all of the junkyards within a reasonable distance. So far, the limited number of units that I've found (four in all) have been unacceptable because of damage.

Consequently, I hate to bother you with this, but do you have any suggestions that you could help me with ? Thanks.....

Mickey Pledger, mpled3559@aol.com
Reply from WW:
From our records, I see you're from Spanish Fort, Ala. I'll share with you the e-mail addresses of two builders who have running engines, one from north Alabama, and one from the Florida panhandle. Each of these guys found a good source of engines when they were looking for their own. Contact me again if these leads don't turn up a good motor. Numerous customers have written in saying that a cheap ad in a local newspaper quickly provided them with very inexpensive cores. One way or the other, we'll get you started on the engine part of your project.

Subj: Crank End Play
Date: 12/1/03

I just ordered your new video on engine assembly. The first one was really helpful, and I look forward to the new addition. I did it online, so there wasn't any allowance for the $5 discount for Corvair Flyer subscribers. No big deal because even at $25, it's a deal.

I did assemble my case, and the crank and cam rotate real nice, but I don't seem to have any endplay. I'm going to take the case apart to see if there are any burrs or problems, but do you have any suggestions on what to look for? Thanks,

John Krumrine, Zenair 601XL, State College, Penn., jqk4@verizon.net
Reply from WW:
Thank you again for your order. And thank you for understanding on the discount. We'd specified check or money order payments so we wouldn't have to give PayPal its percentage on top of the Flyer Subscribers Discount.

If your engine turns freely by hand, in all likelihood, it has sufficient end play. You really have to push the crank back and forth quite hard to measure it with a dial indicator. Even engines which have almost none on assembly end up with 5 or 6/1000ths after an hour's worth of operation.

Subj: Crank Shipping
Date: 11/30/03

We are building a Zenith 601 and plan to use a Corvair engine. Your Manual was very helpful in helping us decide which engine to use and what models we should use.

At the present time, we have a crank that is within specifications that we would like to exchange for one of yours. I made a box out of half-inch plywood to hold the crank for shipping. I guess my question is: How should we ship the crank to you?

We do not believe in reinventing the wheel and we are open to any suggestions that you might have concerning our project. Sincerely,

Robert & Shaun Rehmel, Manual 5602, Zenair 601, Richmond, Ind., Traveler601@earthlink.net
Reply from WW:
Thank you for your positive comments about the Manual. We're shooting to have our own 601 done by the end of January. We're going to make all the installation parts available in both drawings and finished parts, and additionally make videos just on the 601/Corvair combination. This should keep reinvention to a minimum.

When shipping a crank, I've found the best way to do it is to wrap it in old carpeting. All other types of padding fail to hold up. UPS commonly drops boxes 3 & 4 feet (we know people who work there). Carpet inside a box holds up to this fairly well. At this point, you can send your crank to our new hangar at 735A-3 Air Park Road, Edgewater, FL 32132.

Subj: Corvair Engines
Date: 11/29/03

I have been looking for Corvair engines and have found someone with two. I am probably going to buy both. Only one has a bellhousing and I know I need one and I'll either have some spare parts or maybe I can help someone else who is having trouble finding one. You mention in your Manual to only buy an engine you can turn over. These both have been stored inside for the past 15-20 years. Should I go ahead and buy them even if they won't turn over? I know. I know what the Manual says, but if these are what I can find, will I be way off base to buy them? Thanks in advance,

Marv, Marv@myrealbox.com
Reply from WW:
If the engines are in the $100 range, and they don't turn over, they may still be worth buying. If an engine won't turn over, pull out the plugs and look to see if one or two are completely rusty. This means the engine was filled with water at one time, and this isn't good. If they just look dirty and it won't turn over, chances are it's something less damaging.

Subj: Corvair Powered Midget Mustang
Date: 11/28/03

I would like your opinion on the Midget Mustang powered by Chevrolet. I like the fighter aircraft looks and am a classic airplane and car fan. Am I going the wrong direction with this? Thanks,

jolledwa@isu.edu
Reply from WW:
I've already built one motor mount for a Corvair engine to go on a Midget Mustang. A friend of mine at our airport has one that's 90% done. After studying the installation, it's a good match. There are several other guys working on the combination, but no one has flown it yet. Before starting one, make sure you'll fit. It's a small airplane. It should be understood that it's not an easy airplane to build. You don't have to be a genius, but it will take longer than other planes. You can search the past months' Q&A pages here at www.FlyCorvair.com with Ctrl + F for mustang and find several pictures and comments.

Subj: Oil Filter
Date: 11/27/03

Thanks for your Manual. It is a great study. The first video description mentions re-curving the distributor. How much detail does it go into, i.e., could I re-curve/re-build the distributor myself after viewing the video?

Also to other Canadians looking for Corvair blocks, there were tens of thousands of these cars made up here and they are around. After six months of on/off looking and calling, I found two side by side in a small northern town. Be patient. Thanks,

Martin Bima, STOL-Vair, Winnipeg, Canada, mbima@hydro.mb.ca
Reply from WW:
If you're a hard core do-it-yourselfer, there is a lot of good information in Corvair Engine Assembly Video I about how to rework the distributor. However, in almost every case, it's much easier to get the completely Remanufactured Distributor from us. If you study all the work and parts that I put into our Dual Ignition Distributors, you'll see that it is a very low profit margin item in our catalog. I keep it this way because I feel that everyone who is flying a Corvair should be using my Dual Ignition System. I don't want anyone on a tight budget to choose a less desirable ignition system for financial reasons.
Subj: Super FRED
Date: 11/26/03

I had a Son "William" October 4th and have been rather busy, but now I am thinking of Super FRED again.

The O-164 Corvair is considered by Eric Cluton as too heavy. However, his A-65 is 6" in front (mags are recessed into the FW) of the firewall and has an installed weight FWF minus the prop of 216 lbs. What is included in the 205 pounds - intake, and welded tube exhaust? I figure the mount at 6-8 lbs.

Matt Naiva, Wauwatosa, Wisc., steamlaunch@softhome.net
Reply from WW:
Congratulations. 205 is intake, no exhaust. Motor mount 5-7 pounds. My guess is that there'd be a lot of work in successfully reworking the FRED for Corvair power. But you're a clever guy, and I'm sure you could get it if you wanted it bad enough. Just for inspiration, consider that a Heath Parasol Model V has been successfully flown hundreds of hours on Corvair power.

Subj: Odd-fire imbalance
Date: 11/25/03

In the "Engine Beat" section of the December 2003 Kitplaness issue, John Larsen was critiquing the new Bombardier V220/V300T engines. I'm wondering about his statements regarding horizontally opposed engines. I'll paraphrase: 4-cylinder horizontally opposed engines are naturally balanced due to a power stroke every 180 degrees (in phase with the basic layout of the engine). Six-cylinder horizontally opposed engines, however, are NOT naturally balanced (he says) because the cylinders fire 1.5 times every 180 degrees, making them "odd-fire" engines (the power strokes are out of phase with the layout of the engine).

I was wondering if you could comment on Mr. Larsen's observations (possibly prompted by the Bombardier reps?) and speak to the types of mechanical and geometric balance required for a smooth running, reliable aircraft engine in your Q&A section. You mention on your Web site that Corvairs run like sewing machines. Does Mr. Larsen have a significant and valid point about horizontally opposed 6-cylinder engines? And if he does, how is this "odd-fire" phenomenon compensated for?

I know I said I'd shut up until I'd ordered your Manual and videos, but I thought that this article raised some interesting questions that might be worth responding to on the big stage of your Web site. Excuse me if this has been covered exhaustively already. If such is the case, I'd appreciate guidance to the section so I can learn something about it.

Terry Bendickson, La Crosse, Wisc., Terrben@aol.com
Reply from WW:
I know John Larsen and have met him personally. He's usually right about engine issues, but he's clearly mistaken in this case. He does not know what an even firing engine is. The Corvair motor is certainly an even firing motor. The actual definition is any motor that has equally spaced firing impulses. I don't know where his claim of broken 6-cylinder cranks comes from. The NTSB records show that quite the reverse is true. Six-cylinder engines have a phenomenon known as power lap, where the firing impulses overlap each other because they occur frequently enough. This significantly lowers the stress on the engine. Four stroke engines with five or fewer cylinders do not exhibit this characteristic and therefore are subject to internal stresses not seen in engines with six or more cylinders.

Subj: 601XL
Date: 11/24/03

I have come to your Web pages via a link on the Zenith 601 page. I have recently started my second Zenith project. The first a 701, and now the 601. I had been considering using a Jabiru 3300, but feel like Christmas has come reading all of your info. The ability to save substantial costs safely on the engine will allow for better avionics etc. I do have several questions for you, however. The cowling is always a concern on engines other than those the manufacturer uses. I see from Zenith's Web page you are building a 601 yourself using the Corvair engine. Will you keep me updated on how you are doing the cowling?

The second area of interest is the motor mount and exhaust system. Do you have these available or plans for them?

The final question is regarding turboing with the props you have. I live in Colorado on the front range and will be looking at flying at altitudes of 16,000 feet or more to clear the numerous fourteeners we have here in Colorado if I want to fly point to point without numerous diversions. I would also like the ability to get in and out of the mountain strips past 7 in the morning. I look forward to your reply and doing business with you in the future. Thanks,

Michael Armstrong, Zenith 601XL, #5207, EAA # 674318, ma80904@netscape.net
Reply from WW:
Over the next few months, I'll have all the 601 pieces available. Currently, I have the motor mount jig, and the cowling mold is not far behind. For guys operating on a budget, I intend to share drawings of some of the pieces.

My turbo engine is close to operating. All the plumbing, instrumentation, etc. is matched to my 601 airframe, so when the time comes, it will bolt right in. The Corvair is perfectly capable of mild turbo boosting. I think the 601XL, with its generous wing span and area, and sizable engine compartment, is a logical turbo airplane. 16,000 feet seems doable. But of course, the proof is in the test flying. We'll keep everyone posted at the www.FlyCorvair.com 601 Page.

Subj: Corvair/701
Date: 11/23/03

Came across your site this day and your information on the Corvair engine. I have always thought they would make an excellent aircraft engine. I am about to buy a kit for the Zenair 701. I noticed that the 601 has been mentioned. To your knowledge, could this engine be used in the 701? Have you had anyone inquire about such an installation? I would be most interested. I have been thinking about the Subaru EA81, but after my recent reading about weight, etc., the Corvair sounds as if it would be ideal. I am certain you are a very busy fellow, but if you could find the time to share this info with me, it would be most appreciated--Respectfully yours,

Terry O'Dacre, jto@monarch.net
Reply from WW:
The Zenair people tell me the 701 airframe was really designed around engines lighter than a Corvair or O-200. They asked me not to encourage people to install a Corvair in a 701. I'm sure somebody's going to fly the combination, and we have customers working on it. But out of respect for the family's wishes, I don't promote it. On the other hand, the 601 can easily handle engines in the Corvair's size category, and that's why we've chosen it for our own airplane.

Subj: FBI - Flyer Back Issues
Date: 11/22/03

I would like to purchase the back issues of your newsletter and the drawings for the new low profile Front Starter Brackets. I have Manual #5423. Please reply with costs and I will deposit the funds to your PayPal account. Thanks so much!

Al Manley, Longmont, Colo., amanley@attglobal.net
Reply from WW:
The back issues of The Flyer cost $10 and we cover the postage. The original Front Starter Bracket drawings are in Issue #4, and the back issue set is a booklet that includes Issues 1-4.

Subj: Engines
Date: 11/21/03

My name is Angelo Ferraro, and I'm a 601XL builder. Since the beginning, I was convinced that I needed at least 120HP for the plane to fly well, and this is more than the Subaru EA81 can deliver. Since I don't want to spend $15,000 for so called aviation engines, I elected to go for a Subaru EJ2.5 hoping that I could keep the weight down to 300 pounds... But I think it will be more like 350 pounds.

I can keep the power down by programming the computer, but it's the weight that I am concerned about. You are working on a turbo version of the Corvair - maybe that will do. I must confess that I am completely at a loss when it comes to motors. I don't even know what a spark plug is. So could you please, when you have some time, let me know what you think of all this. Best regards,

Angelo Ferraro, aferraro@videotron.ca
Reply from WW:
The 601 will fly very well on as little as 80hp. It has generous wing area and span in the XL model, and I have no doubt a standard 100hp Corvair will make it a fine flying airplane. We will probably fly our turbo Corvair 601 in the middle of next Spring. An engine like this would be 120hp with the standard size Corvair, 135hp or so on a large displacement engine. But I again emphasize that either one of these would be a turbo option, rather than a requirement. Understanding engines is fairly simple. Like anything else, you can learn about it by reading or asking people questions directly. If you have a local airport, this is a good place to start.

Subj: Starter/Generator
Date: 11/20/03

A thought occured to me as I looked at the pictures of the starter and alternator. If you used a generator/motor, could you start the engine using the proper pulley setup for charging? And does such a generator/motor exist? Or is an alternator such a superior device that one wouldn't want to mess around trying to save 20 pounds? Anyhow, I will order a Manual in the near future. I love Corvairs! We had six at one time. Thanks,

Kieran, kieranmays@tds.net
Reply from WW:
The only time in aviation where starter/generators were used was on early jets. These engines had extreme space requirements, and it was easy to mount a starter/generator straight in the nose of the engine. They haven't appeared on any piston engine aircraft that I know of. A starter/generator is always a loser in the weight department compared to a starter/alternator combination. Thank you for your interest. Write with any other questions you have.

Subj: Corvair/Vision
Date: 11/19/03

I'm Danny Johns. My question is whether a Corvair is going to be powerful enough to fly a full size Vision & not the Fold-A-Plane? Thanks for your reply.

Danny Johns, dfgpro@bellsouth.net
Reply from WW:
Fold-A-Plane is a building technique that's applicable to one-, two- and four-seat Vision aircraft. The Corvair motor is the design engine for the single-seater, and a good option for the two-seater with the EX extended wing. Fold-A-Plane tends to produce very light parts which require almost no filling or sanding. The Corvair is the most economical engine available to two-seat Vision builders, but it does require building a fairly light version of the airplane. The Fold-A-Plane technique makes this easy to achieve.

Subj: Avid
Date: 11/18/03

I met you at the Quickie fly-in in Kansas a couple of years ago. I sold my Q2 and now have an Avid MK IV with an NSI Subaru in it. My wife and I were thinking of an Avid Magnum or the equivalent Kitfox next, but don't like the complexity and weight of the water cooled engines. Seems like the Corvair is lighter than the Subaru? The six cylinder Jabiru is nice but $$. Seems like the Corvair is a natural for the Kitfox/Avid aircraft. I have to have a 25 lb. weight at the tailwheel now with the Subaru. Thanks,

Pierce Stewart, Avid MK IV, stewinttdrs@mail.telis.org
Reply from WW:
On a number of aircraft that were formerly Subaru powered, we've completed and flown direct drive Corvair installations. I can assure you that the standard Corvair would be significantly lighter. Options like 190cid Corvairs and the potential of using aluminum cylinders would further the Corvair's weight advantage. While it is true the core Subaru motor is light, by the time the reduction and the plumbing are done, it's frequently heavier than an O-235. As far as I understand, an Avid Magnum was originally aimed at engines in the 150-160hp range. It may fly well with less horsepower, but I'd check this out first. The standard late model Avid would certainly be a good match for the Corvair. If you'd like to see what one of our customers is doing with his Corvair installation in an Avid, check Dennis Smith's Web site, http://fp1.centurytel.net/aero-Smith/.

Subj: Corvair/CH601/Sonex questions
Date: 11/17/03

I'm new to the EA scene, so forgive me if you've answered similar questions before. I have read your FAQ by the way. First let me say that the Corvair sounds like a great step up from the VW. I am looking for an engine I can maintain myself at a resonable cost. Like you, I'd like to opt for a kit that will get me into the air relatively quickly (5-6 year projects are nice, but I want to go flying!). So it has come down to one of the 601 or 701 planes from Zenith, or the Sonex.

The 601s are cool, can accommodate the weight of the Corvair, and more importantly, you're already doing the bulk of the work! Not having flown in one, I have read they handle nicely. I really can't decide on which model 601 yet. What about putting a Corvair in the 701?

More importantly, I really like the Sonex design, and after speaking to a number of people, I have two questions for you:

1. Are you discouraging the Corvair out of respect for the designer? The weight of a 3300 Jab is pretty darn close to the installed Corvair...is the Corvair really such a bad match with the Sonex?

2. I have heard that there are weight and balance issues with the Sonex when one uses the recommended low-weight engines. Wouldn't this be partially alleviated with a slightly heavier (but more powerful) powerplant?

If you have had test flights in both planes (601 and Sonex), which one were you most impressed with in terms of flying qualities? Like I said, I think the Sonex styling wins hands down, but when one considers engine options and kit-confidence, Zenithair really starts to take the lead. Hope you can help me out. Thank you in advance for your time!

Rob, schaumr@hotmail.com
Reply from WW:
The Zenith people tell me that the 701 is really best off with engines lighter than the Corvair or O-200.

Many people are talking about installing a Corvair on the Sonex, and one has flown, but it is a tough match, and I promised John Monnett that I would not market the Corvair for his airframe. Can be done, but not easy, and I will not make a mount for it. The Corvair is about 35 pounds more than a 3300. This is significant. I dont really think the plane has real W&B issues, just different envelopes.

The Sonex is smaller. It is also a stronger plane. I build FWF parts for the 601, and it is an easier plane by far to put a Corvair on. They both fly well, but I suspect that the 601 will fly slower. They are both good companies, run by honest people.

Subj: 140 Distributor
Date: 11/16/03

Received the Manual (5797) last week. I have read it through a couple of times and it gets a little clearer each time. I have never attempted to remodel an engine before so this is going to be fun.

I do have a 1964 block and appropriate heads. However it does not have a fuel pump or distributor. I have found a distributor for a 140hp engine. My question is whether this can be rebuilt by you for my engine, or should I continue to look for a distributor off a 110hp engine? Thanks.

H. D. Yarbrough, Salmon, Idaho, yarbro@salmoninternet.com
Reply from WW:
Any late model distributor can be used for a core. I can rebuild any one into an aircraft grade dual points ignition. Fuel pumps are available fairly cheaply, and it's not worth searching out a core.

We're trying to keep a dozen Remanufactured Distributors in stock. Let us know whenever you're ready.

Subj: Flying Corvairs on a Davis
Date: 11/15/03

Thank you for all that you have done and are doing! A love of aviation and a thin wallet lead me to homebuilts. Airframes are fairly cheap, used instruments can get you by, but that darned powerplant. A spent engine with maybe 100 hours left on it is the least expensive at $5000-$6000? New engines-ha. Rotax looked like the answer, then the 912 got certified and doubled?tripled? in price.

So auto conversions! I love the Mazda rotary, but single rotor 80-100 horsepower are talked about but don't make it to the party. I had given up after a long path down VW motors lead to buy everything new for $6000, and then get 70 horsepower. So use the twin rotary at 170 horsepower on a different airplane. Won't even tell you how many sets of airplane plans are littering the house. (It is under twenty.) Then, heck, ultralight engines must be easier to come by! WRONG. Now I am looking at the two cylinder Corvair conversion by UltraVair that led me to your site and information.

Or heck - just build the Davis DA-2B with a Corvair powerplant (it is a set of plans I own). Thanks for keeping the dreams alive!

Neale Eyler, EAA #0526930, neyler@cessna.textron.com
Reply from WW:
Thank you very much for your e-mail. We saw our friend Jim Ballew this summer. He lives in Oklahoma and has about 500 hours on his Davis DA-2B.

Isn't it great how an affordable powerplant option fuels the imagination with so many possibilities of airplanes to build. And now, our old friend Fletcher Burns even has the 1/3 Corvair Ultravair motor. The Corvair has made a lot of people's aviation dreams a reality. If you want to get a look at a Corvair-powered Davis DA-2, check out Jim Ballew's Davis DA-2 at www.FlyCorvair.com.

Subj: Distributor Core
Date: 11/14/03

I am writing on behalf of Dan Palmer, Conversion Manual #5489 owner. By way of introduction, I am a retired Corvair repair person (I had my own shop), having built over 70 engines from the crank and cam up and have coached and supervised 12 to 15 people in building their own engines besides doing all the regular Corvair engine and mechanical work. Many, many years ago, I also took courses in wood aircraft construction and A&E Certification. The A&E should indicate that I am very much out of date.

I have read your Manual three times to digest your information and had some questions that Dan asked you and Richard Finch at the EAA meeting in Wisc. BTW, Richard has been a member of our Corvair club for some time. Dan has purchased a 1966 95 hp 9:1 engine from me and is in the process of cleaning, machining and accumulating parts for future assembly. On Page 18, you state that since the cam and ignition timing are replaced, there is no effective difference in a 95 hp 9:1 and 110 9:1 motor. My question is, which distributor should I give to Dan to send to you? In our shop, we had the same 1960 model Allen Tune Up distibutor machine and set up many distributors (we had specs and correct part #s for the many different distributors for different hp engines made by GM ) to correct parts houses' errors and mechanics installing the incorrect distributor. Do I give him a 95 or a 110 shaft? A 95 or 110 point cam? Which weights do you require? On Page 50 you state that you make adjustments to the advance weights, springs and stops. The shafts had many different size holes for the advance stops. Can I give him any, non 95 or 110, very good, very little worn shaft? The shaft posts were sometimes very badly worn, as were the holes in the advance weights. I still have most of these used items on hand.

Are there still AC44F plugs available? I will send you our 5th printing of our club publication booklet, The Care & Feeding of Your Corvair, for your perusal. Sincerly,

Sylvan Zuercher, Albuquerque, N.M.
Reply from WW:
Sounds like you have a real good background in Corvair motors. You should be a real asset to Dan's progress. As far as distributor cores go, I'll take any core you have which has the larger roll pin holding the gear on. I buy a steady supply of cores from Corvair automotive sources to supplement the cores people send in. Generally, about half the parts find their way into the wastebasket. I ask people to send us their cores so I have a steady supply of incoming material. I do them in batches and very rarely do I actually send the same distributor back. As you're aware, there are numerous different shafts, cams and counterweights. I have about six different combinations that will produce the desired results. Flight distributors are made out of a combination of parts from different distributors. AC44F plugs are available still as the resistor plug, R44F. Thank you in advance for the booklet.

Subj: TBO, Instrumentation
Date: 11/13/03

I am a prospective CH 601 HD builder. I have my plan set and will be building from plans, at least to start. Although I feel I am a long way from needing to make an engine decision, I have been looking around and discovered several builders on the Zenith board discussing the Corvair option.

Can you give me an estimate on the TBO on a freshly rebuilt Covair engine, or is there some way to tell when an engine needs re-build?

I'm also curious about engine instrumentation other than the tachometer - I found the info for that on the Web page. I am specifically interested in EGT and CHT probe locations and choices as well as normal operating ranges. Of course all of this may be answered in your Manual. Thanks in advance for any assistance,

Bob Lindley, travliman58@hotmail.com
Reply from WW:
An overhauled Corvair motor done to the specs in my Conversion Manual should easily go 1,000 hours. An engine such as this could be built for about $3,000, and when overhaul time arrives, the complete overhaul will likely cost less than $800. I have fairly good indications from flight testing that the engine may truly last 1,500 or more hours, but I'll wait till we get there to make it a statement of fact rather than a goal. When operating a Corvair engine, you'll know when it reaches TBO, just as you would if you were operating a certified engine. The engine will have above normal oil consumption, and have lower compression as measured by a differential compression tester. Additionally, if you're using oil analysis, you can spot trends in the engine's lifespan. We measure CHT with probes underneath the sparkplugs. The Corvair has one-piece cylinder heads, and generally one probe on each bank will give you a very good picture of CHT. Any EGT gauge style you like can be used on the engine. Each gauge manufacturer will have a recommendation for probe placement.

Subj: Corvair KR2
Date: 11/12/03

I was interested in puting a Corvair engine on a KR2. I was wondering how much they weighed and if there are any KRs with Corvairs on them. Thanks.

Matt, MSHUBAT@aol.com
Reply from WW:
Our Web site, at Flying Corvair powered planes at www.FlyCorvair.com, contains links to several flying KRs, including photos. The main Corvair FAQ page also contains data on weight. Most of our conversion parts work well on KRs. Most KR guys begin the conversion process with the purchase of one of our Conversion Manuals. It contains all the information you'll need.

Subj: Ragwing II and the Corvair
Date: 11/11/03

First I wanted to say I enjoyed your part of the Pietenpol presentation at Sun 'N Fun 2002. That is where I really got interested in the Corvair motor.

I am wondering what you think about the Corvair in Roger Mann's new Ragwing Wing Special II RW26. He is showing the Rotax 912 in the plane. I am interested in his RW26 because I am 6'4" tall and it is designed for a person of my size with the ability to bring along a second smaller person.

Thanks for all you do for the sport, and I enjoy your articles in the Experimenter. Thanks.

Chris Steckmann, Vidalia, Ga., EAA#0566212, talltwo@cybersouth.com
Reply from WW:
I've not personally seen a flying Ragwing aircraft, nor examined one structurally very closely. I'm not familiar with all the different models of his aircraft. One or two people who I know personally have said some of his earlier designs were very lightly built and not suitable for powerplants like a Corvair or O-200. I'm not sure if the RW26 is different from its brethren. Perhaps the appropriate thing for you to do is ask Roger Mann if the aircraft is appropriate for engines of the O-200's size and weight category. If it is, it can handle the Corvair.

Thank you for your positive comments.

Subj: Zenith Zodiac XL Support
Date: 11/10/03

I will be purchasing a Zenith Zodiac XL as soon as I sell my acreage, and I am at the planning/prepping/education stage of the project right now. I have been comparing many engine configurations for the Zodiac XL, and yours looked interesting. I am just a first time builder, so I would feel comfortable with more support, for example: the engine, engine mounts, reduction units, props, cowl, etc. supplied, so that I can basically bolt it on and go ... i.e., a firewall forward package or kit would be interesting. Knowing your engine can be supplied by you for $6,499, how much would it be for a firewall forward "package"? Any info would be greatly appreciated. Thanks! Regards,

Mark Mutschlechner, Allied.Seismic@pulsedatainc.com
Reply from WW:
In the next few months, we're working our way up to having every firewall forward piece for the 601. Even if we built your engine for you, test ran it, etc., I don't think the parts could possibly top $9,000, including the prop, cowling, mount, etc. Please follow along on our www.FlyCorvair.com 601 Web page and we'll have everything posted there. Keep in mind, however, the Corvair is a very simple engine (it has no reduction unit, it's direct drive), and you could save thousands of dollars on this estimate by building the motor yourself.

Subj: Turbo Parts List
Date: 11/9/03

In previous conversations and assorted posts you have mentioned that you will soon have the air turbo-Corvair finished, tested and unveiled. I am currently waiting on hold for this grand event. My engine has been disassembled and thoroughly cleaned, but I don't want to move forward until I hear what parts I should order that differ from those mentioned in your Manual, or what (if any) special machine work will be required. So the freshly-cleaned engine parts are sitting in a box collecting dust. While the grand unveiling may be a ways off yet, do you at least have a list of parts that I should order, or any special machining instructions that may be required. Also, are you considering writing a supplement to your Manual for these special conversions? I know, I for one, would gladly pay for such a supplement.

Bill Howerton, Bill@Howerton.com
Reply from WW:
I released three-quarters of a page of turbo information in the latest issue of The Corvair Flyer. Have you seen a copy of the newsletter? In short, the only internal difference you may wish to consider is utilizing a TB-10 camshaft. It's available from Clark's, and its part number is C-8801, or C-8801R if you wish to use a regrind. With that, you can go ahead and assemble your entire motor. All other changes are external. I still find the time to work on the turbo motor, but I don't see us flying it until spring. However, I'd like to have it running on the test stand long before then.

Subj: SA-7 and Corvair Engine
Date: 11/8/03

Thanks for your response. I reviewed your parts list. Looks good. I understand Corvair engines came in 164cid and 190cid sizes. Seems like the 190 would be a lot closer in torque to the O-200 recommended for the Skycoupe. I imagine they are a lot rarer than the 164. Can the 164 be converted to 190? What drawbacks might there be? And it seems to me that only low RPM engines like the A-65 ever develop their full at the propeller power potential - at around 2,300 RPM. How would the Corvair be with a reduction drive? Too heavy?

Mike Smith, Skycoupe, EAA Chapter 511, Shenandoah Valley, Va., turkeyridge@cat4.net
Reply from WW:
The 190cid motor is a modification of the standard 164cid, as explained in detail in The Corvair Conversion Manual. Primarily, the modification is machining it to adapt 94mm VW pistons and cylinders. It's approximately a $1,000 option on the rebuild when you consider it as a price increase over the standard 164cid rebuild.

Gary's Skycoupe has very good performance on a very mild 164cid conversion. It has a solid 100mph cruise on a 4.5 gallon per hour fuel burn at 2,600rpm. The Skycoupe plans show it to be approved for engines as small as 65hp. 100hp is not the minimum recommended engine. Most Skycoupes were built with 85s.

I'd respectfully differ with your opinion of engine thrust above 2,300rpm. An A-65 makes its rated 65 horses at 2,350 rpm; an O-200 makes its rated 100hp at 2,700. If you've flown the same airframe on these two different engines with properly matched propellers, you would clearly agree you could feel every single one of the O-200's extra 35hp. Prop efficiency at low rpm is largely a myth perpetuated by people who have done no direct testing with their own hands. Virtually all engines certified since WWII have been rated at 2,700rpm. If it weren't efficient to transfer power at these rpms, they would not have built these engines.

Although there may be some airframe that may benefit from having a reduction drive on a Corvair, the Skycoupe isn't it. It is an elegantly simple, solid airframe which is best matched by a simple, inexpensive, direct drive Corvair motor.

Subj: Corvair for Vari-eze or Taylorcraft
Date: 11/7/03

I have attended your demos at both Oshkosh and Lakeland, and I am very impressed with what you are doing with the Corvair engine. I was wondering if anyone had ever installed a Corvair engine in a Vari-eze or a clipped wing Taylorcraft. At present time I have a Great Lakes Bi-Plane which I have just about completed, and I am starting to consider what my next project will be. I am leaning toward the clipped wing T-Craft, but whatever I decide to build, I would like to have it powered by a Corvair. I would appreciate your comments and thoughts. Best regards,

Steve Davis, stephone@lexcominc.net
Reply from WW:
At least one Corvair powered VE flew. We have several people working on them, but it is not my favorite combination. The plane doesn't have a lot of versatility. I like planes which can land on grass.

Grace owns a Taylorcraft BC12D and looked into buying a clipped one last year. A Corvair would power either one.

Subj: RE: Zodiac 601 XL/Corvair
Date: 11/6/03

Thanks again for the quick response. My only thought of buying a turbo motor was for the nitrated crankshaft, but evidently Corvair engines are different from VWs. I built a EMPI "inch pincher" in the '70s and had to make sure the crankshaft was nitrated for the addition of turbo boost.

Well, let's get me started. I will locate the best engine I can, but before purchasing it, I will call or e-mail you to make sure it is suitable. I will also order your Manual, because I think I would be happier with the Corvair than the Revmaster 2100/turbo I have been looking for. My reasons are evident. Thanks again, and I will be back in touch.

Bob Geerhart, Zodiac 601XL, Carson City, Nev., thegeerharts@msn.com
Reply from WW:
While it's true that Corvair turbo and 140hp crankshafts were Tufftrited, I have a significant amount of flight testing on standard Corvair crankshafts, as well as cranks ground .010/.010, proving the standard Corvair crankshaft is suitably durable even for demanding flight applications.

Let me highly recommend you arm yourself with the Conversion Manual before you start shopping for egnines. The Manual and supplements including videos and The Corvair Flyer newsletter are available at The www.FlyCorvair.com Online Catalog. Occasionally you'll stumble across what appears to be a good buy, and it pays to have the information in the Manual at your disposal to save you from purchasing an unsuitable conversion candidate.

Subj: Zodiac 601 XL/Corvair
Date: 11/5/03

I read about your engine in the recent issue of Contact! magazine. And now while reviewing the Zenith Web site, I notice you are building a Zenith for your Corvair.

I live in Carson City, Nev., with an airport altitude of 4600ft. In the summer, density altitude can be quite high, and I will be flying into and out of other airports of equal and/or higher altitudes, so I think I would like to use a turbo on any engine I use. As the Zodiac will handle engine weights up to 265 lbs., I don't think that would be a problem if your engine can handle a turbo. The aircraft also has enough fuel storage to handle any length flight I would want to make. Any enlightenment you might give me would be appreciated. Thanks.

Bob Geerhart, Zodiac 601XL, Carson City, Nev., thegeerharts@msn.com
Reply from WW:
The flying turbo does not use any parts from the land turbo. Turbo car cores are expensive. The Conversion Manual covers all models of flying motors. Any good 1965-69 95 or 110hp will make a good flying turbo motor core. Our 601 will be turbocharged, but not right off the bat. The first motor we'll fly in it will be a straight-out-of the Conversion Manual, naturally aspirated, 100hp engine. After logging some time on this, I'll install a pre-tested turbo engine. I'll keep everybody posted on the developments of the turbo motor through the Corvair Flyer newsletter.

Subj: Corvair Flyer
Date: 11/4/03

I enjoyed your presentations at Oshkosh this year, and have been keeping up with your Web site and the discussion groups. I have obtained a very nice core engine with all the correct numbers. I may start the rebuild process this winter.

At Oshkosh I wrote a check for $30; for a year's subscription of your newsletter and copies of the past newsletters, but have not received anything, yet. BTW, I purchased manual #5169 at Oshkosh July 2002. Can you tell me of the status of the subscription and back-issues? Thanks,

Tom Hubbuch, Louisville, Ky., hthomw@yahoo.com
Reply from GE:
For being so patient and understanding, you'll be the first one outside The Corvair Authority Hangar to receive the Official Book of Corvair Flyer Back Issues.

William is still working on the Fall 2003 issue of The Corvair Flyer, and I'll get that in the mail as soon as it's complete. There's a lot of new stuff going on, so it will be a very full issue.

Subj: Teardown video?
Date: 11/3/03

I have the Corvair Engine Assembly Video II and have enjoyed it a couple of times already......... I'm looking forward to number III.

Have you given any thought to making a "teardown video" for a used motor in-tact, to pieces laying on the table, to pieces that need to be saved, to pieces for cores, etc.

Bob Moore, bobandlindamoore1@msn.com
Reply from WW:
Yes, we've given this more than thought. It's scripted, organized and ready to be shot. Our video genius, Merrill Isaacson, will be producing this one also. It's actually more difficult to film than any other video we've done because we need to find a core that's suitably difficult to disassemble so that we can show all the techniques for removing stuck nuts, etc. We're looking to have this video done by Christmas.

Subj: Awesome video
Date: 11/2/03

You folks are great!!! I have just returned home after eight days on the "Fire" line. I work up in Lake Arrowhead, California. I am in the water department up there. We have been running diesel fuel round the clock to standby generators to keep the pump stations running so they can have water as needed. The video is awesome, can't wait to get the rest of the series. Thanks,

Doug Blackburn, Yucaipa, Calif., twinboom@msn.com
Reply from WW:
Good to hear that you guys are winning the battle against the fires out there. The third in the Engine Assembly Video Series will be out shortly. We'll keep everybody posted. Besides the compliments, the most common comment about Video 2 was that it was short on funny outtakes. Believe it or not, we left them off out of a misguided attempt at the appearance of professionalism. But, the builders have spoken, and Merrill will go back to the traditional format of information first, outtakes at the end.

Subj: Aerobatic Corvair
Date: 11/1/03

I am very interested in the Corvair engine for its reliability and low cost. I am planning to design and build a Sport Aerobatic plane in the coming year. I note fuel injection for Corvair engines is not recommended. Can this engine be utilized with other carburetion and inverted oil for aerobatics in the 100 to 110 HP range??? While I have done some work with engines, I do not consider myself an engine person. This is not to indicate that I would not use this outstanding engine on other designs. Thank you for your assistance.

Benny J. Clark, texaswings@cox-internet.com
Reply from WW:
Although anything can be done with time, money and skill, I think that the Corvair is not for aerobatics. No one has ever broken a crank in a direct drive Corvair flight motor, but I am not sure if the crank is strong enough for real harsh aerobatics. You would spend a lot of time and money putting inverted systems on a Corvair, and in the end, very few people are looking for less than 200hp in single seat acro planes these days. I think your efforts would be better spent on other engines.

Subj: Aluminum Cylinders?
Date: 10/31/03

Maybe this is a stupid question, but would you save enough weight by casting aluminum cylinders/fins around a steel or iron liner to make it worth the cost?

Richard Pike, rwpike@charter.net
Reply from WW:
I believe the true weight savings available with a ferrous liner in an aluminum jacket is on the order of 12 pounds. But, there's a lot of testing and development work needed to ensure the combination is good. A couple of guys are looking into this, but as yet, there is no proven product. It's been done on a lot of engines, so it can be done on a Corvair. We just want to ensure that it's fully developed and tested before anyone calls it a product, rather than a project. Even when it's done. I believe 90% of Corvairs will still fly on steel or iron barrels. They're very economical, and thus make sense for most people.

Subj: Oil Pan/Alternator
Date: 10/30/03

I noticed that your Oil Pan does not come with a drain plug installed. On the Pan that I have on order I would appreciate if you would install an automotive type drain plug before shipment as I don't have the tools to do the job. Also, I don't know if a belt comes with the alternator kit. If not, I would appreciate if you would include a belt with my order. Many thanks.

Chuck Mulloy, cdmbam@yahoo.com
Reply from WW:
Many guys have mentioned the same issues about the Oil Pans (I ship the light weight aluminum Oil Pans without the drain plug drilled because there are several different styles of drain plugs which customers choose from). To serve the needs of everybody, I now have a Pan Installation Kit which includes a magnetic draing plug, installation hardware, and a rebent stock pickup tube. You can check the www.FlyCorvair.com Online Catalog for more information on this. As for the Front Alternator Kit, it will include not only the belts, but every nut and bolt to do the job. The design is frozen, tested and proven, but they're not quite coming out of our subcontractor yet. They'll be done very shortly.

Subj: Cross Country Corvair?
Date: 10/29/03

I would like to know what plane you would recommend for use with a Corvair engine that would be best for efficient, high speed cross country flights, while still being inexpensive to build?

patrickm_rio@hotmail.com
Reply from WW:
There are a number of aircraft that meet your definition in various forms. An important issue is: How large are you? If you're in the range of 5-foot-9 and 170 pounds, a KR2 can make a very impressive cross country performer with a Corvair engine. If you're larger, something like a Zenair 601 will provide more room, but will not be quite as fast. If you're inclined to build in composites, you may want to consider a 2-place Vision with an EX wing. With Steve Rahm's Fold-A-Plane technique, the aircraft can now be built with a substantial amount of time savings. If you'd like to consider a timeless classic, a light weight Wittman Tailwind could easily hit 150mph on a Corvair engine. All in all, there are a number of aircraft well suited for cross country work on Corvair power.

Subj: 140 motor
Date: 10/28/03

Can I use a 140 short block and turn it into a 110 motor?

Curtis, loc4115@yahoo.com
Reply from WW:
A 140 shortblock can be used to make an airplane motor; 95 or 110 heads will bolt right on. The only serious consideration is if the motor was from an automatic transmission 140 engine. These engines had a 4 degree retarded crank gear. This would have to be replaced. The Conversion Manual covers this in greater detail. Identification of the 140 retarded gear is covered in the Book of Back Issues of the Corvair Flyer, available along with the Manual and other helpful supplements like videos, at the FlyCorvair.com Online Catalog.

Subj: Alternator
Date: 10/27/03

Curious why the pulley for the alternator is mounted in front of the starter main gear and not behind?

John Esch, jesch@earthlink.net
Reply from WW:
If you study the installation carefully, you'll see several factors at work:

1. In order to have a short, stiff starter mount, it's best to have the Ring Gear as close as possible to the engine.

2. Although the John Deere alternator is very thin, you still have to have the Pulley moved forward so the alternator can be mounted in front of the cylinder head.

3. If the Pulley was behind the Ring Gear, you'd have to pull the Ring Gear off to change the belt because the belt would not pass between the Starter Nose and the Ring Gear.

A good question, and it illustrates how many small technical details can be behind a simple thing like Pulley location. By the way, I didn't think all this up myself. It's the same way a Lycoming is mounted.

Subj: 601XL/Corvair
Date: 10/26/03

I am currently building a 601XL (Construction log at www.peoamerica.net/N601WR) and am becoming very interested in the use of the Corvair engine instead of the Jabbaru (sic?) I was originally planning for. I have not purchased the FWF kit and probably won't for about a year.

Will it be possible to purchase a ready to install engine and FWF kit from you by 2005? If so, how about a wild guess as to the cost. I would want electric start and pretty much all the other bells and whistles.

P.S. I've added a link to your Web site on mine in the engine section.

W.R. "Gig" Giacona, wr.giacona@cox-internet.com
Reply from WW:
I look at builder's Web sites all the time, and found yours attractive and different. I like the X-ray vision on your home page, and the color coded completion planview for the wings. Thank you for putting a link to FlyCorvair.com on your Web site. We'll have another update on the 601 at www.FlyCorvair.com/601.html in a few weeks.

I'm planning to have everything on the 601 project done and available by Sun 'N Fun 2004. I plan to have all the 601 stuff available as plans, parts and eventually complete firewall forward packages. Thus, we'll be happy to help you with any of your engine needs when the time comes.

Subj: Corvair for Rans S6S or KitFox?
Date: 10/25/03

I am considering the Rans S6S and the KitFox IV or V as possible kits to build. I would like to know your opinion as to the suitability/performance of the Corvair engine in these planes.

I really appreciate all the information on your Web site. It is very helpful in trying to learn about alternative engines and their technology.

H. D. Yarbrough, Salmon, Idaho, yarbro@salmoninternet.com
Reply from WW:
I know what an S6S is, but don't know the design well enough to know if it's capable of handling an engine the size of a Corvair. We have one or two builders nearing completion of Kitfox Model IVs, but I think the Model V is a better candidate for Corvair power as it's substantially beefier.

Subj: TBO
Date: 10/24/03

The Jabiru has a TBO of 2000 hours, the Rotax a lot less. What is the estimated TBO of the Corvair ? Thank you,

rconnors@adelphia.net
Reply from WW:
At an utter minimum, I'd put the Corvair's TBO at 1,000 hours. While many engine companies throw around very high TBO numbers, it is my personal opinion that only new and factory zero-timed Lycomings and Continentals have consistently demonstrated hitting a 2,000 hour TBO. Corvair engines overhauled according to my Conversion Manual may eventually prove themselves at this level. However, even if the Corvair's TBO turns out to be less than 2,000 hours, its low overhaul cost will more than make up for a shorter TBO. We have good indications that the Corvair may go 1,500 or 2,000 hours, but I have not yet flown them this far. So it remains a goal. If you convert the Corvair yourself, you obviously can overhaul it and save yourself quite a bit of money. The primary reason why the Corvair doesn't rapidly wear is the fact that we operate it at such a low percentage of its automotive rated output. While most conversion companies want you to operate at 100-130% of rated land output, we're asking only half of this from the Corvair.

Subj: 601 FWF package
Date: 10/23/03

Another e-mail just to say thanks. And to let you know that I, for one, am hoping that you might consider a kit type of install for those of us who are ignorant of a lot of the engine matching of carbs, manifolds, where to install manifold pressure gauge, CHT, EGT, etc., etc., or perhaps a specific sheet with that info for those of us going the Corvair/601 route ... A basic here's the exhaust, here's the intake manifold, the alternator bracket and the alternator package ...or at least a parts list and drawings. I don't mean to presume on your good nature. I am sure there is a way that you can be compensated; at least I would be willing, since all of this stuff is new and I need guidance. Without you I would not even consider this type of project. So, again, thanks...All my best,

Jim Dankovich, Zenair 601XL, Troy, Mich., jdankochiro@yahoo.com
Reply from WW:
I intend to keep all the 601 guys fully informed on all the 601 stuff I do. I've traditionally released plans and drawings for everything I've done, even if I sell the same part. This way, I take care of guys on both ends of the financial and skill spectrum. Keep an eye on the FlyCorvair.com 601 Web page for updates.

Subj: Corvair in a float plane
Date: 10/22/03

I have a J-6 Karatoo I built from plans and have been flying for 10 years with a 65 Continental. If you are not familiar with the Karatoo, it looks similar to a Taylorcraft. It flys great and performs well with the 65. The 65 is a little tired and I am thinking about repowering. I would also like to put it on floats some day. It weighs about 670 empty. Would a Corvair be a good choice for this type of plane on floats? Would it be necessary to use a reduction drive to get more thrust? Would appreciate your opinion.

Gordon Slattery, gordon.slattery@polarisind.com
Reply from WW:
I'm familiar with your airplane. If it's been flown by other people with an O-200, I'm sure a Corvair would be inside its limitations.

We have a fairly good judge of the Corvair's performance vs. the A-65 because we gauged the performance of our Corvair powered Piet against those with A-65s many times. A Corvair, as converted by the standards in my Manual, is a clear winner. The engine produces substantially more thrust, even direct drive.

Subj: Honing
Date: 10/21/03

What grit or RA do you recommend for the cylinders when getting them bored, honed, and going to use chrome rings?

John Esch, Independence, Ore., jesch@earthlink.net
Reply from WW:
A standard wall finish is perfectly fine for chrome rings. It is only plasma molly rings that are really finicky about wall finish. A lot of people worry quite a bit about glazing rings, or rings not seating, but with a little common sense, I've never found this to be a problem on the Corvair motor.

Subj: Shop manual and Finch books
Date: 10/20/03

I have been looking online for the 1965 Shop manual and the Richard Finch books, but I can't seem to find them. Could you direct me to the Web sites?

Robert, Zenair 601 XL, Australia, RVROBERT@bigpond.com
Reply from WW:
The books you're looking for are available from Clark's Corvairs, whose address is in your Conversion Manual.

Subj: CID & Prop for 601
Date: 10/19/03

I have just received the Conversion Manual, thank you!. I have also seen the information on the Zenith site as well as your Web site regarding the XL and I have decided to build the XL rather than my original choice of the 601HDS. Could you tell me what size engine and prop type combination you are intending to use, as I will be duplicating your aircraft. Regards,

Robert, Zenair 601 XL, Australia, RVROBERT@bigpond.com
Reply from WW:
I intend to use a standard 164cid Corvair with a 2-blade 66" Warp Drive prop on my 601. I may later install other engines, but I believe the first order of business is to demonstrate how well the standard combination will work. The second engine we test will be my turbo model. You can keep up on 601 news at the www.FlyCorvair.com 601 Page and on turbo news in greater depth in The Corvair Flyer newsletter.

Subj: SA-7 and Corvair Engines
Date: 10/18/03

I have a Skycoupe project and did not even consider a Corvair engine until reading your article. I live in Virginia and wonder about the availability of a rebuildable engine, what it would cost and could I, who rebuilt a Renault engine on my picnic table once, do it safely. I have a VW engine I have pulled apart and am not confident in it (it is much too small anyhow, I bought it for another project since abandoned, and looks rather fragile). The guy shown flying the Skycoupe, would he sell plans for the firewall forward installation, especially the motor mount? Thanks,

Mike Smith, Skycoupe, EAA Chapter 511, Shenandoah Valley, Va., turkeyridge@cat4.net
Reply from WW:
I built the motor mount in the Skycoupe. Gary is a friend of ours who lives about 90 miles away. He has about 60 hours on it now, and likes it a lot. I'd be glad to provide you with measurements, photos, etc., of his installation if you decide the Corvair is for you. I featured the Skycoupe installation on my Introduction to Corvairs Video as well. My Corvair Conversion Manual also contains detailed plans for motor mounts, and instructions on fabricating them. The Manual is the starting point for builders, and also will help you locate and select a suitable, rebuildable core. The Manual, supplements like videos and The Corvair Flyer newsletter, and conversion components are all available at the www.FlyCorvair.com Online Catalog.

Subj: Corvair HP, Prop Tip Speed
Date: 10/17/03

I'm looking into building a Fisher Dakota Hawk from FFP. It's all wood and fabric construction, and rated for A-65, C-85, O-200 and Rotax 912s. I posed the Corvair question to the "fishnet" builders board, and got an interesting reply. The Gent kindly told me that at best, turning 2300-2500 RPM at the prop, one of your conversions will only pump out around 65hp. Is this true? How do you manage to swing a prop at the hp figures of 3000-3300 RPM for the 100 and 110 hp versions? Wouldn't the prop tips be supersonic? I'm hoping this is all bull the guy is feeding me - I like the alternative of the Corvair. However, I don't want to find out the hard way that I needed more ummph. Thanks for your reply.

Bryan Wood, bryanwood@gra.midco.net
Reply from WW:
There are many well intentioned people who want to offer advice, but have never tested any of the engines they're willing to comment on. I've owned and tested an enormous array of engines, both certified and experimental. Additionally, I've been a dealer for many types of propellers, and was the ranking U.S. employee for MT Propeller, the highly esteemed German aerobatic prop manufacturer. When I offer advice, it's based on this type of experience, not hearsay. At 2,300rpm, a 65 Continental or a Corvair will both make about 65hp - this is correct. Importantly, so will an O-200. But unlike the C-65, the Corvair and the O-200 can turn more rpm and make more hp, and yes, make a good deal more thrust.

Virtually every aircraft engine certified in the U.S. since WWII makes its rated power above 2,700rpm. The ubiquitous Cessna 150 made its rated power at 2,750 on a 69" prop. There are a lot of nice people who'd have you believe somehow that if the engine was turned down to 2300rpm and a 72" prop installed, the engine would magically produce more thrust. Obviously this is wrong. For an application like the one you're thinking of, a 68" 2-blade Warp Drive prop on one of my standard Corvair conversions turning 2,800-2,900rpm will provide performance that falls between a C-90 Continental and an O-200. Such a FWF package would cost substantially less than $4,000 for you to overhaul and convert. It will run smoothly and reliably, providing years of service. In my experience, no other engine in the category can even come close to the Corvair economically. The simple response for anybody who tells you otherwise about Corvairs is, "Have you ever flown one or tested it with instruments?" The answer from the kindly gents always trails off into something about knowing somebody who did once. I'm patient with these guys because they mean no harm. But old wives' tales like this are the enemy of people who want to go flying on a budget.

P.S. Please copy and post this in its entirety in response to your group.

Subj: Zodiac 601XL
Date: 10/16/03

Got my Conversion Manual the other day, thanks a lot! Still searching for my engine, but I'll get paperwork back to you well before I need to start buying your parts.

Boy! I sure like the plane you've picked out! I've been bouncing back and forth between building the 601XL and the 701 for the past month. Would love to have the better STOL characteristics of the 701 as I've got a nice field that would be plenty long enough for the 701 but probably not the 601. I too don't think the 701 is Corvair friendly as the weight just will be too much for the plane. This leads me closer to picking the 601XL as I WANT to use the Corvair engine. I just can't bring myself to spend over $10,000 for an engine for an experimental plane. At any rate, it looks like I'll be stretching out any building for the next several years. Love to get a ride once you've got yours finished. Thanks for the encouragement you give in all your communications.

John Lifer, Jliferjr99@aol.com
Reply from WW:
We will have at least monthly updates at The www.FlyCorvair.com 601 Page. I'm pretty convinced the 601 will be able to operate out of a fairly short field. The XL model has a lot of wing area flaps, and doesn't weigh much more than the 701. The Zenair factory advises me that the 701 is best reserved for very light engines.

Subj: Corvair in Canada?
Date: 10/15/03

The Corvair conversion seems to be quite a good and cheap alternative 100Hp engine...I'm in the process of choosing the airplane I will eventually start building and the XL601 has been on the top of my list for some time...Which is good considering the choices we have today. Budget is the thing (ain't it for eveyone of us but the wealthiest...) and the Corvair could fill the gap for a cheap conversion engine. I'm presently holding the start of my project because of engine price...

But the problem is: Can I find a decent Corvair block in Canada??? Most people I talk to about this engine are looking at me as if I was speaking about UFOs... I live in the province of Quebec (near Montreal). If you have any info, please, let me know.

Yvon Bourdeau, Canada, yvon_bourdeau@yahoo.com
Reply from WW:
About 8% of my customers are Canadians. Even in the remote provinces, they've all been able to find engines at reasonable prices. Although the exchange rate makes it a little more expensive for our friends in the north, the engine's still an excellent deal.

Subj: Zenith XL
Date: 10/14/03

My name is Dr. Lynn Muller and I am a marketing professor at the University of South Dakota. I am also presently constructing a Zenith 601 XL, and I am very interested in the Corvair engine. I will be following your progress very carefully. I feel that I will be looking for an engine during the Spring of 2005, and although I like the idea of building my own, feel that I would be better off purchasing a conversion engine from you directly. I was wondering what kind of lead time I would have to provide you, and would a completed engine come with the necessary motor mounts and instrumentation? When do you estimate the completion of your XL and when might we anticipate getting access to performance spec's. Would a starter equipped engine still be within the allowable weight?

Lynn Muller, Zenith, South Dakota, lmuller@usd.edu
Reply from WW:
We're going to post an update on our 601 project once a month to start with at The www.FlyCorvair.com 601 Page. Eventually, when everything's all worked out, I'll offer an entire engine package. Currently, I do offer most of the pieces to do the job at the Online Catalog. All of the engines I build use electric start. Write us any time you like.

Subj: 601/Corvair
Date: 10/13/03

Allow me to introduce myself. I'm Robert Noffsinger from the Wichita, Kansas, area. Recently, I have been interested in purchasing a Zenith Super Zodiac CH 601 XL kit, but I have a question for you. What is the viability of substituting a 120hp Corvair engine for the recommended Lycoming 0-235? I'm more concerned about weight and of course degradation in performance (if any). As I am in no hurry to purchase the kit, only reply when it is convenient for you. Thank you in advance for your valued perspective and advice. Sincerely,

Robert Noffsinger, Kansas, moffsin@lsil.com
Reply from WW:
Here's how highly we think of the 601/Corvair combination: We bought a 601 for ourselves. Check The 601 Page at www.FlyCorvair.com, as we'll be posting progress reports on our 601XL taildragger. The first powerplant we'll be running will be a straight 164cid Corvair conversion, so builders can appreciate the performance available with a standard Corvair conversion. Only later will we be testing more powerful and larger displacement Corvairs.

Subj: Corvair/601 Cowl
Date: 10/12/03

I am 80% done with the airframe on my 601 XL... am wondering if the Lycoming cowl from Zenair is likely to be a good choice for the corvair ...am planning to purchase your new starter kit...thanks for all your work...Jim

James Dankovich, Zenair 601XL, Troy, Mich., jdankochiro@yahoo.com
Reply from WW:
Check out our new www.FlyCorvair.com 601 Web page Monday. Yes, the 235 cowl will work with the installation I'm developing, but I'm also planning on producing a more streamlined custom cowl. My Front Starter Kit is going to be an integral part of all my 601 work.

Subj: Corvair Conversion, 601
Date: 10/11/03

My name is John. I am a new student pilot (2 hours solo) and have dreams of building my own plane. I have been doing a ton of research and I think I am going to build Zenith's Zodiac XL. I have seen some Web sites that mention the Corvair conversion (CC) and I was wondering if you thought this would be an acceptable airframe for such a conversion. I saw on your site that the CC is not a fit for the RVs, but I have not seen anything on Zenith. I am looking forward to building my plane and I would like to do as much as possible; I do not really want to uncrate and bolt on an engine. I would also rather put the money saved into the detail of my airframe if I have a trustworthy engine bolted on. Please let me know your thoughts on this. Thanks for your time.

John, poopoopappy@hotmail.com
Reply from WW:
Check out our new www.FlyCorvair.com 601 Web page Monday and read about our project. I think the 601 is a really good airplane, and the Corvair will prove itself to be an excellent match for it.

Subj: Front Starter Kit, Buttercup
Date: 10/10/03

I just purchased your Conversion Manual #5767. I wrote you a note on the return paperwork. I am just wondering if you received it and read my comments? And I hope you don't take anything the wrong way. It's not that I don't want to buy your parts, it's just that I'm one of those guys who likes to make everything himself. So again, if I could get the part #s and drawings for all of the Front Starter and Alternator setup, that would be greatly appreciated. If you need a few bucks for that, no problem. And I am going to subscribe to the newsletter. My plan is to build a Wittman Buttercup as cheaply as possible. I have a lot of parts and materials. I have found an engine and am disassembling it right now; very interesting design. Please return e-mail with your thoughts. Thank You,

Todd Sutton, Wittman Buttercup, tsutt@myclearwave.net
Reply from WW:
Sorry if we haven't had a chance to respond to your note. We have updated all the part numbers and drawings for the Front Starter Kit since the last time the Conversion Manual was re-edited. All of these drawings and part numbers are included in back issues of The Corvair Flyer (available as a collection for $10 for U.S. delivery, $15 for international delivery including Canada, payable by check or money order to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802).

At Oshkosh this year we met Earl Luce. I think the Buttercup is an excellent choice as a Corvair airframe. Steve Wittman was a real genius and Earl is a straightforward guy.

Subj: O-190
Date: 10/4/03

A few friends and I have lost our minds. We have decided that flying is not fun any more in aircraft that you have to spend more time flying than looking outside and actually enjoying the scenery. I have a Tripacer that's down for overhaul, and my other two buddies have a 182 Cessna and a Cardinal RG. We want an airplane that is safe at low speed and is economical (read cheap to keep and operate), something we're not used to. We have decided upon the Pietenpol with the engine of course being a Corvair. I like plenty of H.P. and subscribe to the theory that you can never have too much power. Is an O-190 Vair engine tremendously more expensive to build than the 164 cu.in. version? What about the rh rotation option? What about dual carbs? We think 3000 feet is plenty high enough and at that altitude a mixture control isn't really needed is it? I have a complete Buick 215 engine with BAP reduction installed, but this would probably be too much for a Pietenpol, or would it, what's your opinion. Any advice and answers you have would be greatly appreciated. I'll probably be ordering you Manual in the near future just in case we all use Corvair engines. Thanks

James Adams, jtadams@ev1.net
Reply from WW:
A Pietenpol will certainly fly very well on a standard Corvair motor. Many of the highest time Piets are Corvair-powered, and my current conversion is much more powerful than any built to Bernie's specifications. The 190cid Corvair ups the cost by about $1,000. Not the end of the world, but keep in mind that my standard Corvair motor would do 105+mph in my Pietenpol. We rarely flew at high altitude, and the mixture control on my Piet was wired full rich.

I've seen a picture of a direct drive 215 in a Pietenpol, although I'm not sure what modifications were made to it to make it work. Its installed weight, even direct, will be at least 120 pounds more than a Corvair. Although Piets are strong airplanes, in my opinion this is overdoing it. The 215 is a good engine. I've built several, and even flown behind one. It's just not the right engine for your plane.

Subj: Zenith, Sonex or RV for Corvair
Date: 10/3/03

I am currently finishing up a 6000 mile trip around the US visiting kit manufacturers to decide what to build. I have visited Van's, Sonex and Zenith. My wife fell in love with the CH701 and CH801 STOL Zeniths. Would a Corvair engine be too heavy for the 701? I assume it would not have enough punch to get good STOL performance from the 801 (?). Thanks -- will be checking in on e-mail from the road as we progress.

John Collins, San Diego and Panama, oldguyflier@yahoo.com
Reply from WW:
The 701 is a very light plane, and the factory advises me that builders should respect the 200 pound FWF weight limit. There are several people building Corvair/701s, but this is far from a blanket recommendation. The 801 is too much airplane for a Corvair motor. Personally, if I were building an 801, a 360 Lycoming would be my first choice.

The 601 is Zenair's best product for the Corvair. We have one, and you can see our progress on it by checking in at our www.FlyCorvair.com 601 Web page.

None of Van's aircraft are appropriate for a Corvair motor, with the possible exception of an RV-3. We know the Monnett family well, and John has told me many times that a Corvair motor is too big for the Sonex. You can read more about these at the Sonex Application and RV Installation sections of www.FlyCorvair.com.

Subj: Serial numbers to look for?
Date: 10/2/03

What is the lowest s/n engine I should purchase? What are s/n's of the early 164 cid engines. Thanks,

Bill, mrchips@coinet.com
Reply from WW:
Chevrolet did not use sequential serial numbers on Corvair motors. They have numbers stamped on them, but it's an encrypted date code of production, and the same number will appear on several different engines of different models that were produced in different years, but on the same day of the year. The way to differentiate engines is by letter codes and cylinder head numbers. All of the good combinations are covered in the Conversion Manual at great length, in addition to where to find a good engine and how to transport it. Let us know any time you're ready for a Manual. They're available for $59 in the U.S. ($74 for international orders, including Canada) by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the www.FlyCorvair.com Online Catalog.

Subj: 'Vair Ez
Date: 10/1/03

Is the VariEze compatible with a Corvair? Is there an inexpensive conversion to fuel injection and electronic ignition? Are these worth their expense? How is your turbo project coming?

patrickm_rio@hotmail.com
Reply from WW:
A VariEz is not one of my favorite aircraft, due to its fairly high landing speed and comparatively poor pilot protection in an accident. If you gave me my choice of aircraft to have an off-field landing in, a VariEz would be near the bottom of the list. Most VEs are overweight, and the Corvair motor is slightly heavier than the recommended hand prop Continental. This is a weight sensitive airframe, where a few pounds are not to be taken lightly. A LongEz is the same fuselage with a much larger wing. Most people think it is underpowered with 100hp.

My Conversion Manual goes into great detail on why I do not recommend fuel injection nor electronic ignition on single-engine aircraft built by amateurs. Simplicity and warning of impending failure are lost if you opt for fuel injection and electronic ignition. While they may offer slightly superior performance to traditional systems, their characteristics of complexity and no warning failures are extremely undesirable in single-engine aircraft.

I continue my work on the turbo, and it will likely fly first on our 601. We'll keep you posted at www.FlyCorvair.com

Subj: Corvair/Titan
Date: 9/30/03

I'm planning to build a Titan IIS (pusher). Would one of your Corvair engines with electric start be appropriate for this configuration?

Rich Latta, Linwood, N.J., rlatta7259@aol.com
Reply from WW:
I have developed many engine installations and components for the Corvair motor. Almost all of this has been done for traditional, plans built, tractor aircraft. I know what a Titan Tornado is, but have never looked at it for the purpose of installing a Corvair motor. Being a kit and an outgrowth of ultralight technology, the airframe may be too lightly built for a Corvair, or may not have drawings available for me to use to work up an engine installation. Without questions like this answered, I'm not able to offer you much assistance beyond the engine itself.

Subj: Corvair in Mini-Imp
Date: 9/29/03

Dude.....Help..... I've got this engine that has the the following codes: Heads: 3856759; Case: 3819616; Engine: TI005RD. But I can't find 8409 anywhere on the crank?........ Now I'm wondering if the cylinders or the case are any good for converting....... What's up?......Do I have a mixed matched engine here or what ???? Thanks...I. A.........

Robert Parker, rpa2976@earthlink.net
Reply from WW:
Your engine is a 1965 110hp and it's perfect for the conversion. It is not a mix and match engine. All of the numbers you've given me here indicate that the engine is a matched unit. The head number and case letter code are in your Conversion Manual as good numbers. There's also a picture in the Manual showing the location of the 8409 numbers on the crankshaft. You're in good shape. Keep going.

Subj: Manual Update
Date: 9/28/03

I bought the Manual from you a couple of years ago (1999 version) and I see that there is now a new update. My Manual # is 2036. I was wondering if I could send you this one back and pay the difference to get the new updated Manual.

Also, what are your thoughts on buying a case, heads, cam and crank from a catalog and scratch building an engine from parts? It seems like this is about all you use from the origianl engine, so what is the advantage of buying an old engine, ripping it all apart, and throwing 50 percent of it away? I realize there are lots of bolts and gaskets and stuff, but the catalogs sell kits of these things too.

Jason Baker, jasonjamesbaker@comcast.net
Reply from WW:
There are quite a number of parts that we use from a core motor, far more than you're thinking of at this point. You'd spend a whole lot of money to buy them individually. You're much better off buying a core motor. We have hundreds of people building Corvairs, and we've had to find a core motor for only a handful of them outside Australia and England. Most people find them in their hometowns.

The new Conversion Manual is greatly expanded over the edition you have. It's now 100+ pages. If you mail in a copy of the cover of your old Conversion Manual, along with a completed Liability Statement, available at The Corvair Authority Liability Statement Page, the cost is $30 for delivery in the U.S. payable by check or money order to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802.

Subj: Corvair for STOL
Date: 9/27/03

I am a private pilot that had to sell of my share of a P140 to put money down on our house when my wife and I got married. Now, it is not all that bad because a condition of marriage (Like right before the service!) was to start work on my dream within 5-6 years. Well I am at year 4.5 and my wife is very supportive. Mostly because her and the kids have been subliminally subjected to countless hours of aviation video, TV, toys and in sundry forms of propaganda.

At any rate, I just want to say that I try and keep as much informed about the culture as possible. I wish to express strong congratulations on your contribution in this culture beyond just the business side of aviation but obviously expanding on the very essence of the sport and culture of aviation.

I look forward to pursuing a Corvair powered 2-place STOL build solution in the upcoming future. And now a request of opinion. Zenair 701/Corvair combination? I have seen a few 601s, but that is a totally different craft. Any other rough field 2-place STOL A/C that in your opinion that could end up on a pair of amphibs eventually? I know many say match power to the A/C, but I am just so impressed with the Corvair community

Regards and great work for your community.

Derek Hulbig, Ontario, Canada, hulbigd@rogers.com
Reply from WW:
The Zenith people try to discourage builders from installing engines which weigh more than 200 pounds firewall forward on their 701 design. However, there are a number of other designs which could be successfully operated on amphibious floats and successfully operated at 100hp. These include airplanes like the Pegzair and some J-3 replicas.

Hats off to your wife for understanding that men who are passionate about airplanes make better husbands.

And thank you for your kind words.

Subj: Less horsepower
Date: 9/26/03

I have a '63 Corvair engine with new pistons, rods, OT-10 cam and cylinders.

I was thinking of using this engine, even though it has less horsepower than the newer engines, because I will have to fly on the new Sport Pilot License.

I want to build a KR2S and slow it down with a climb prop and a lower H/P engine. I will also have to find a way to slow down the landing.

Aside from the low H/P, is there any reason not to build this engine? I haven't started yet and maybe I can trade the Corvair Club here for newer case and heads but I don't really need all that power. Thanks for any help you can give.

Patrick Driscoll, patrick36@usfamily.net
Reply from WW:
There are a number of reasons that make the 1964-69 engines more desirable. Forged pistons, for example, are readily available for the '64-69 motors, but much harder to find for the 1960-63s. I highly recommend you go back and search out a late model engine. A simple set of flaps might very well get a KR2 with the S wing into the Sport Pilot category. Good luck with your building. It's certainly a worthwhile endeavor.

Subj: Heads, cranks, distributors
Date: 9/25/03

After sitting my butt down long enough to read more of your Conversion Manual, I did manage to find the page that lists the number for the correct heads and they are the 9:1 heads. Head number on both are: 3856632.

Do you also replace or could you replace the main gear on the shaft on every hub you do? Do you, upon request, replace the distributor gear? Mine looks a little worn. I plan on packaging up my crank and sending it down your way here in a week or two. Also, I would need to get the .010 oversize main bearings, correct? Thanks in advance.

John Esch, Independence, Ore., jfesch@earthlink.net
Reply from WW:
Your heads are 1964 110s. They are perfect for the conversion. Keep in mind that you will need to use 1964 cylinders with these. On your crank, I can replace the gear for $100, labor included. I have many spare distributor drive gears, and if there's something wrong with yours, I'll change it at no charge. Yes, you will need .010 under bearings.

Subj: Corvair for T-40
Date: 9/24/03

I'm considering building one of the Turner T-40 planes, preferably one of the two place variety. A buddy from work has just picked up a Corvair engine for his Air Camper, and the simplicity, convenience, price tag, reliablity, etc., etc. has peaked my interest. The T-40s range in hp from 85 to 150. Would the Corvair be a candidate for a T-40, and if so, which one(s)? Do you know of anyone who is building such a plane? Thanks for any help you can provide.

Jason Porter, jporter147@comcast.net
Reply from WW:
We get a question on T-40s once or twice a year. I strongly suspect the reason why the T-40 design stays around is because they were featured in some of Tony Bingelis' How-To books. In all the airshows I've ever attended, I'm not sure I've ever seen one in person. There are downsides to building a design which may not be currently supported. I'd investigate this fully before deciding to build any design. As to the Corvair's applicability, if the plane flew on an 85, it will certainly fly on a Corvair motor. Keep in mind that the 85hp version may not be the two-seater you mention.

Subj: Prop Hub
Date: 9/23/03

You may have received my phone message this a.m. re: my checking out a local shop to make the prop hub. I expect you chuckled all the way to wherever you were headed as you are probably aware that your price for the hub is a "steal," "real deal," "bargain," you name it. I sort of thought that was what I would discover. I shall be ordering one in the near future.

If you have some spare time, I would enjoy discussing the Christavia Mk-II/Corvair project in Canada where builder thought it necessary to use Volkswagen reduction gear to attain good cruise and climb. Seems he thinks it can't be accomplished straight out of the box with direct drive. I am starting a similar project but heed your words re: direct drive, keep it simple, etc.

Enjoyed your first forum at OSH.

Roy Rogers, Manual #5594, carolandroy@tds.net
Reply from WW:
I've worked very hard to keep prices down over the years. Glad to hear from another guy who appreciates it.

My experience with direct drive Corvairs suggest a good, simple flying plane can be had with a direct drive motor. The Christavia is a fairly efficient airframe, and I'm sure a direct drive Corvair would have no problem pulling it.

Subj: Ultravair
Date: 9/21/03

At Oshkosh this year, an ultralight had a 1/3 Corvair engine on it and I really want one. Now I fly a Kitfox Lite with the 2SI 2-stroke engine.

I really hate the idea of cutting a good block for the 1/3 engine (similar to cutting a VW in half) and am looking for a block and crank (164 cid) that has damage anywhere except the rear (flywheel) 1/3. You can take a look at the engine at http://www.ultravair.com/index.html. I have called salvages around here and no one has any Corvairs. If you know any such engines, please let me know. Thanks, Stan

Stan, stan33o@yahoo.com
Reply from WW:
Fletcher Burns, Mr. ultravair.com, is a friend of ours and I think he's on to something good here. As for your engine search, we've tossed away a lot of motors that would have been useful for his conversion, but don't have any currently. Put out the word in your hometown that you're looking for one and it shouldn't be too hard to find. Hundreds of our customers have found engines without much trouble.

Subj: Corvair Specs
Date: 9/20/03

I was wondering what the max. cylinder size could be for standard pistons. I have the tools to hone the cylinders, but not to bore them. I am trying to find out what the max. reading could be so I can use standard pistons. I cut the ridge out and there was none to speak of. I know that Clark's says they will hone cylinders and if they take off less than .006 you can use standard pistons. But I don't know what a standard cylinder measures. Thank you for your help.

Jim Sury, jimsury@fbtc.net
Reply from WW:
The stock bore is 3.437. We have built motors with standard size TRW forged pistons, and I think it's best to keep the wall clearance to about 5/1000" or less; 3 would be minimum.

Subj: Corvair Engine Search, Jr. Ace
Date: 9/19/03

I e-mailed you earlier about a Corben Jr. Ace with one of your engines. You e-mailed back that the plane was damaged and no longer flying. Thank you for getting back to me on that.

At any rate, I'm on the search for a Corvair to convert for my Corben Jr. Ace. I've found three near me in Missouri. Here are the numbers: TO8267 (supposedly 110 HP, had a manual transmission); TOI27RD (supposedly 90 HP, had automatic transmission); TO325ZF (don't know diddly about this one).

Please help with these two key questions: 1) Can you confirm which are 110 HP and suitable for the Wynne conversion? 2) If I choose to go with the manual transmission engine (TO8267), how tough is it to find an automatic bell housing for the conversion?

I plan to purchase your Manual and various other parts from you. However, I first want to make sure I can find a decent engine to convert. My Corben Jr. Ace will hopefully be another successful Corvair bird. It's a good airplane, just very underpowered. It's actually a Baby Ace Model E which has a 26.5 foot wing span. Solo performance isn't bad, but performance is bad with another average sized human sitting next to me. Thanks for the help. It's greatly appreciated.

Greg Bacon, Prairie Home, MO, gbacon67@direcway.com
Reply from WW:
Of the engines listed, the one with the RD suffix is a 110 1965-69. It is your best bet. When people tell you things like "90hp Corvair motor," they're guessing - there was no such thing as a 90hp Corvair motor. The RD was a manual transmission motor, but this does not matter. You can cut either bell housing down to make a front cover.

As you know, the short wing span is part of your airplane's climb performance issues. I think a lot of people casually acquainted with the airplanes don't notice the Pober airplanes' longer wingspans. In the 26 foot range, you'd be surprised how much a foot or 18" on either side would improve the climb performance.

Subj: Scale Drawings
Date: 9/18/03

Last year I wrote to you concerning the GN-1 Aircamper steel tube frame. You advised me to get a copy of the old Flying and Glider Manual and go with the Piet steel tube frame. I finally got on the ball and ordered one and I'm thrilled! Thanks for setting me on the right course!

Are any scale drawings of the Corvair engine available so I could work on some cowl designs? (Not that I'm jumping ahead or anything!) Thanks again and take care! Sincerely,

Greg Murphy, Pietenpol, Elwood, Ind., windsock@onemain.com
Reply from WW:
One of the back issues of the Corvair Flyer newsletter (available as a collection for $10 for U.S. delivery payable by check or money order to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802) has good 3-view drawings which can be reduced or enlarged on a copier. These were done by our friend Dan Benson. They reproduce very well.

Glad to hear you're on the right building track. When looking at photos of my Pietenpol, realize I raised the thrust level of the engine up to the top longeron. Flew slightly better, easier to cowl, and looked better.

Subj: Oil System Tests
Date: 9/10-16/03

Friends,

Below are five pictures from oil system tests. I intend to expand on this subject in the next Corvair Flyer.
Above is a 12-plate cooler, with proper lines, sitting in an ice bath. Cold soaking it like this replicates a start at 30 or 40F. Oil pressure is measured on the incoming and outgoing lines.
Above is the stock filter, also in an ice bath.
This three-gauge panel shows:
  • 1. Regulated oil pressure before the filter.
  • 2. After the filter, before the cooler.
  • 3. After the cooler - this is the same pressure the oil gallery sees.

    This run shows clearly that a chilled filter has very little pressure drop, but the cooler is operating on the bypass. I later blocked the cooler lines to verify that the bypass was exactly 10psi.

  • The cooler was soaked in very hot water until it stabilized near 150F. This is a laser infrared thermometer reading.
    With the cooler temperature elevated, it still has a substantial pressure drop. Between the ice and hot water, I also ran an 80F ambient temp test. I was surprised to see that the cooler still used the bypass.
    The oil in the engine was 10W40 mineral oil. The oil system functions just as GM intended. It bypasses the cooler until the temperature comes up. This allows the oil to properly lubricate the engine at any temperature you'd like to go flying at.

    Subj: Corvair Powered Zenair 601XL
    Date: 9/9/03

    Friends,

    Corvair/Colt builder Dave Vargesko and I just returned from a 2,500 mile round trip to the Zenair factory in one weekend. We picked up a complete Zenair 601XL taildragger kit. After speaking with the Heinz family extensively, Grace and I decided that this should be our 2004 demonstrator aircraft. In the next few days, we'll start a new page on www.FlyCorvair.com so other 601 builders can track our progress on this.

    Subj: Piston Pin Pressing Jig
    Date: 9/8/03

    Friends,

    Several questions surfaced recently about the little jig I use to press piston pins. My Engine Assembly Video Part II will be finished this week. It shows the jig in action. I thought I'd share this photo of it to help give people an idea of the shape. I will include a drawing of the jig in the next Corvair Flyer newsletter. Subscriptions are still $20 a year in the U.S., $25 for international builders, payable by check or money order in U.S. Dollars to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card at the Online Catalog of Parts available from The Corvair Authority.

    Subj: Good Head Castings
    Date: 9/7/03

    Friends,

    Here are two photos of the major castings we use for flight heads: the 110 and the 95hp. Please note that there are also engines like smog 110s that have different castings. Use these two photos to identify good heads. You can use two heads with different numbers as long as they have the same chamber shape.

    Above is a standard 110 head. It has a distinctive combustion chamber shape. Please note that early cylinder heads, 1960-63, can also bear a resemblence to the 1964-69 110s. Looking at the chamber shape and checking the numbers against those in the Conversion Manual will identify usable heads.

    A 95hp head is pictured above. It has a straight line defining the top of the flat quench area. Some of these heads are listed as 8:1 compression. In reality, they're slightly higher. The shape shown here, along with the correct casting number for a 1964-69 engine, identifies a good flight head. In my experience, there is very little difference in output of identical engines differing only in 95 or 110hp heads. The factory horsepower differences in these two motors were based on the cam, timing and carburetor jetting. Since we're changing all of these things, and the heads have identical size valves, I have found the slight difference in compression ratio between the two motors to produce a negligible difference in final output. Either motor will produce 100hp when converted according to my Conversion Manual.

    Subj: Bad Head
    Date: 9/6/03

    The photo above is an example of the combustion chamber style that should not be flown. It is known by several slang terms, including open chamber, turbo and smog. The example in the photo is a 3880708 head that we flew in my original tests. The Manual has the whole story on that. In short, this chamber style has no flat quench area, and should not be used in a flight motor. Some of these heads, like the 3878564, came on factory turbocharged Corvairs and are very valuable to Corvair car restorers and collectors. If you have a set of heads like this, there are many car guys who would gladly trade you for a set of the good heads in excellent condition.

    Subj: Completed Engine Storage Time
    Date: 9/5/03

    I am one of those guys who bought the wrong engine before reading your Manual. With your encouragement I was able to locate a set of 110 heads and believe that I am ready for dissassembly. In an earlier communication I believe you mentioned to an e-mailer that you knew of an engine that sat completed for 20 months before installation. I believe this may be my case. Any further thoughts? Thanks,

    Gary, gboothe@calply.com
    Reply from WW:
    The motor could go a lot longer than 20 months in a reasonably dry place. ACF-50 is the best spray I know of for preventing corrosion. If the rods and crank were sprayed with it after assembly, as well as the steel parts of the valve train, it would last many years.

    Subj: Introduction
    Date: 9/4/03

    My name is Jonathan and I am building a Vision. I am 23, currently residing in southern New Mexico, and I'm an enlisted active duty member of the Air Force. I've been serving for over 6 years and I'm a jet mechanic. I worked F-16s for my first four years and the past two years I've been working on the F-117. I've always had a love for flying and I earned my private certificate in January before we deployed for Iraqi Freedom. This is my first attempt at building an airplane and it has been educational while teaching me new skills.

    I flew down for a build session with Steve at the end of July and the Vison Personal Cruiser that Morgan is building is beautiful. The pictures of it with that nice blue engine hanging off of the front are beautiful. In person, it looks even better.

    I have a long ways to go before I finish (I'm completing my HStab right now) but deciding on a powerplant now will help facilitate getting it accomplished when the time comes. I've never put an engine together myself but I would like to do so on this project. My interest for the Corvair engine stems from what I call the ratio of 3: money to power to reliability. A Lycoming 0-320 would be my ideal choice but the total cost of the engine during its life (rebuilds, yearly maintenance) just put it out of my reach.

    The 120hp Corvair engine seems like a good choice but that's just looking at numbers on paper. If you were putting a Corvair engine in a two-seat, VFR, EX wing Vision, which one would you choose, 100hp or 120hp?

    If I make it back to Steve's, I'd love to see your hangar. Thank you for your time, honest Web site, and for furthering experimental aviation. Guys like you and Steve are making it easier and cheaper for guys like me to make my dreams come true. Take care and have a great weekend.

    Jonathan Dingus, Vision, New Mexico, jonathan@jonathandingus.com
    Reply from WW:
    We very much enjoyed your photo. I'd seen it before. When you first sent it out, Steve showed many, many people at our home airport. I come from a big military family, and let me say most Americans, myself included, appreciate you serving your country at its time of need. It's an honor you'll have for the rest of your life.

    The engine you may be most interested in is my work turbocharging the 100hp Corvair. In the end, it will have better altitude performance than a 3100cc 120hp. If it can maintain 100hp at 10,000 feet as I plan, it should exceed the performance of an O-320. My testing indicates that the total parts price in a turbo motor will be less than $4500. If you give me a few more months, I'll have the hard numbers and the system will be fully developed. The Vision is an exceptionally efficient airframe, and it has the space under the cowl required for such an installation. These unique attributes make it a very good match.

    Subj: 10-10, OT-10, Stripped plugs
    Date: 9/3/03

    I did manage to go to the Corvair Underground (CUG) and picked up the chassis manual, their 2004 parts manual, and cost manual. I verified the head numbers and the crank number and I do have a 1964 110 hp engine and 1962-63 102hp engine. Whew! Are the '64 heads the 9:1 heads you recommend?

    I may need to get new (used) heads due to taking out the spark plugs; at least 2 on each head were frozen and I think they are stripped due to the force to get them out and seeing no threads on the plugs. Ouch.

    The insides of the engine look pretty good, which still had badly needed oil change oil in it. I plan on sending my crank down to you to have the grind, safety shaft, and hub job done. Should I take the crank up to CUG and have them check out the crank first to make sure it is usable prior to sending it to you for mods? Can you explain the 10:10 grind? I plan on getting a new camshaft from them and many other parts.

    I will have lots of questions in the near future since my rear end will be relying on the front of my plane. Thanks again,

    John Esch, Independence, Ore., jfesch@earthlink.net
    Reply from WW:
    You can helicoil stripped sparkplug threads in Corvair heads. I've done it on a number of engines, and a great number of certified airplane engines have helicoils in the plug holes.
    Please note that the Corvair Underground does not have OT-10 cams. Clark's and Jeff Ballard, 805 644-0006, are the only two sources for the OT-10 cam. Last time I spoke to Jeff, he had a few on the shelf.
    10-10 means that the bearing journals have been reduced in diameter by 10/1000". This is done on a very special grinding machine that looks like a big lathe. The grinding wheels are up to 3 feet in diameter. Afterwards, you use bearings which are slightly thicker and thus the clearance is restored. This is a common rebuilding practice.
    Almost any Corvair 8409 crank from a running engine can be redone at our facility. Rarely do we get one that will not clean up with a .010 regrind.
    Send me the 7 digit number on the end of your head, but I'm almost sure it will be correct.

    Subj: Chief conversion
    Date: 9/2/03

    I am interested in building a Corvair engine to use in an Aeronca Chief project I have. Has this been done before and can you provide information regarding electronic ignition and fuel injection for this application? Thanks,

    Billy, ltlmtn@charter.net
    Reply from WW:
    I used to own a 1946 Chief. I think it's one of the best classic aircraft ever produced. Its fuselage structure and interior arrangement are exceptionally good.
    A Corvair motor would easily power an 11AC. There are FAA issues involved, unless you're doing a substantial amount of work to the airplane. Corvairs have been fuel injected, and have used electronic ignition, but I do not advocate flying either one of these systems. Neither one of them generally gives any type of warning before failing. Such a characteristic is unacceptable in machinery intended to fly. Conversely, carburetors and points ignition generally give lots of warning when they need attention, and rarely shut off in the blink of an eye.

    Subj: Hose Ends
    Date: 9/1/03

    Friends,

    A number of people have asked for a photograph of the hose ends we use.

    Clockwise from top right are:
  • 90 degree full flow swiveling -6
  • 180 degree full flow swiveling -6
  • Non-anodized -6 end, used for welded fittings, made by Earl's
  • Brass barbed fitting, never to be used in aircraft
  • -6 swivel fitting with 1/8" pipe outlet - good for pressure or temperature sending
  • Same thing made by different company
  • AN833-6D bulkhead elbow - a fitting like this is far more restrictive than a full flow 90
  • Thank you.
    William

    Subj: Front Starter Kit Specs
    Date: 8/31/03

    Friends,

    A number of people have asked questions about how the Front Starter components are assembled. I've added several photographs, a description and instructions to the Online Catalog of Products from TCA at a special Front Starter Kit Link. Also, all components of the Front Starter System are now listed with links to descriptions and pictures at the Online Catalog at www.FlyCorvair.com.
    Thank you.
    William

    Subj: Low Profile Front Starter and Ring Gear
    Date: 8/30/03

    William, what is the smallest diameter ring gear and starter combination that can be had for the lowest view over a close fitting cowling? How much more complicated is it to go to a rear ring gear set to get the lowest view over the nose? Sorry to have missed your outing last Saturday.

    Sam Sayer, Zephyrhills, Fla., Karibird37@msn.com
    Reply from WW:
    The Corvair can use a 10.5" ring gear in the front. Putting the starter on the back of the motor requires modifying the oil system and changing the location of the filter and cooler. This presents a significant amount of complexity which many people do not wish to introduce to the motor. The above photo is a view of my current low profile front starter. You can see more photos at the eBay auction of the 100hp Corvair Conversion I built - but the site is only up until the auction ends Sept. 4. I'm working on a starter nose which will further reduce the current height by 3/4". But I have the setup in the photos available right now, and it requires no oil system modifications.

    Subj: PIET - Road Trip
    Date: 8/29/03

    Had a fun weekend, especially at your place. Can't wait to build up these 6 engines. I am sending you a UPS package, but can't send to a PO Box. Do you have a shipping address?

    Did you look at the three engines you got a call about? If you are not going to buy them, are they avaialble? We still need three more. More Later,
    Barry Davis, Pietenpol, Georgia, bed@mindspring.com

    Each of the six guys from Georgia in the photo above is building a Corvair powered Pietenpol. Look for their story in the next issue of The Corvair Flyer newsletter. We'll be mailing these in early Fall, so be sure to subscribe or renew now.
    Reply from WW:
    We had a great time also. Our hangar address is 210-11 Cessna Blvd., Port Orange, FL 32128.
    There were actually four motors there, and I bought them all. They had been outside for a long time and were really only good for miscellaneous parts. At $60 for all four, the price was right. Keep looking up in Georgia; you're bound to find more with a little work. If anybody in the Atlanta area knows of a source, please e-mail Barry directly.

    Subj: My Corvair engine runs for the first time
    Date: 8/28/03

    Add me to your list of having a running Corvair engine. Attached is a picture of my corvair engine running for the first time on my Pietenpol fuselage. Hope to have the plane finished later this fall. Thanks,

    P.F. Beck, Pietenpol, Barnwell, S.C., pfbeck@barnwellsc.com
    Reply from WW:
    Congratulations! I'm sure it's a proud moment for you. The pictures you've shown us all along have always displayed good craftsmanship and work. I'm sure the engine will reward you with many happy hours of flying. Keep us posted.

    Subj: Which Engine
    Date: 8/27/03

    I received your Conversion Manual today and I can't wait to get started. I will get the one page Registration and Liability Statement sent out here in the next day or two. A little busy here with the forest fires going on here and I have 2 flight crews in my guard unit out fighting them.

    I might have jumped the gun, but before receiving your Manual, I purchased 2 Corvair engines. Granted I might have paid more than I should, but I have 2 engines! I just want to get a clarification on the engines I do have. The last 2 digits on the serial numbers I have are YM and YN. These are the 110 hp and are 1964, correct? Are these the engines with the cylinder heads I should be concerned with and will these engines work for my application?
    I am currently starting my KR-2S (modified) project, after being away for close to a year being deployed to Afghanistan, so coming across these engines has sparked my interest in building again, plus after selling one of our vehicles and the wife giving me 75% of the money for the sale to go towards my KR project. Any advice will be greatly appreciated, since I have never taken apart a piston engine before. Thanks in advance.
    John E., KR-2S, Independence, Ore., jesch@earthlink.net
    Reply from WW:
    You may have jumped the gun. Both YM and YN engines could be either 164cid or 145cid. The only way to tell for sure is to remove the top cover, rotate the crank and look for the 1/2" tall numbers that read 8409. If the crank says 5607, you have 145cid engines. If you send me the number on your cylinder heads, I'll be able to give you more specific information about them. If it turns out that these are 145cids, a good source for you for a 164cid core would be The Corvair Underground. My Oregon geography isn't good enough to say how far apart the two of you are, but he certainly would be able to provide you with the correct core.
    In either case, keep building. We're glad to have you back from Afghanistan, and it's good to hear that you have a very understanding spouse. Your enthusiasm and her support is the proven combination behind many a successful airplane project.

    Subj: Where to Buy Motor Mount Bushings
    Date: 8/26/03

    Gettting ready to mount the Corvair to a copy of Your Pietenpol mounts. Can You give me an idea of where to get those neoprene bushings for the mount isolation? My local car parts guys say there are many different types. Thanks,

    Steve, Elma, Wash., srs1@techline.com
    Reply from WW:
    Above is a photo of the sway bar bushings we use, Energy Suspension Part No. 9.8105RC. They're available from our local Auto Zone. If anyone has trouble getting a set, send $20 payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802. This will cover mailing you a set in the U.S.

    Subj: Suggestions for next Manual revisions
    Date: 8/25/03

    Hey William, I had another suggestion, this time for your next revision of the Manual. (And by the way, this last Manual is a vast improvement over the first one. Great job!)

    Picture this scenario: My hangar is a 50 minute drive from my house. So I drive out to the hangar to work on something, and when I get halfway into a procedure (whether working on the engine or on the airframe), I discover I am missing a particular size bolt or a particular lube or tool or something. Murphy's law says it will be something I cannot get at the Chief Auto Parts, but needed to have ordered last week from Larry's or Clark's or something.

    It would improve the plans immensely if, for each of the chapters (Disassembly, Case Assembly, Rod, Piston, and Cylinder Assembly, Head Assembly, etc. etc. etc.), you had a list of tools required, parts required and materials required. That way, a builder doesn't get started on a particular procedure only to discover halfway through that he doesn't have a particular item that is required. He can make sure he has ordered all the parts and expendables and has all the necessary tools for that procedure.

    I know you aren't trying to replace the Corvair Service Manual, but even for the procedures you do cover, it sure would be nice to have that list in one place, easily digested, at the beginning of each chapter. It would be especially handy for those of us who are doing this for the first time, and have to basically go out and buy every bottle of anti-seize, every can of spray paint, every can of STP, every valve compressor, etc. Thanks,

    Dave Morris, Dragonfly, Bedford, Texas, Dave@davemorris.com
    Reply from WW:
    Your suggestion is a point well taken. I am getting closer to this ideal with my Engine Assembly Videotape Series, which helps people visualize what they'll need for engine assembly. One of the things I've worked on before, which I think would be most useful to builders, in addition to what you've said, is a flowchart on the sequence of building an engine. I saw one of these done for the Sonex aircraft by the factory and it was very, very good. I'll have to put some more time into developing one of these for the Corvair. I'll keep your suggestion in mind as well and put it to work when I can.

    Subj: How many passengers?
    Date: 8/24/03

    Hello! First of all what an impressive engine you have. I'm new in the homebuilder aircraft. I don't have any experience. I'm just wondering: If I built my own plane, can I use multi-engine plane using your engine and how many passengers you think can lift? Thank you.

    Leo Pestano, AandL121699@aol.com
    Reply from WW:
    Thank you for your compliments on the motor. Most single engine Corvair powered planes are two-seaters. A small percentage are single-seaters, and I do not know of any which have flown three or four passengers yet. There are at least five people working on twin engine Corvair powered planes. Four of these are two-seaters. But the sky's the limit when it comes to how many engines could lift how many people. It's easy to imagine a tri-motor that would lift six people, or a four-engine airplane which would carry eight. If you're interested in designing an airplane, the best place to start is with John Roncz's Sport Aviation articles.

    Subj: Hypereutectic pistons
    Date: 8/23/03

    Hello, this is Ted Phillips. I haven't wrote you for awhile partially because of my busy schedule at work and my Corvair re-build! Getting ready to fire my baby up hopefully within the next 30 days. This is a very proud and exciting stage of my plane build. The reason I am writing you (besides catching up) is I feel that as a Manual owner I should inform you of the one deviation I have made from your Manual. I just know that I'm going to get an ass chewing for this, but I have used Clark's Hi-Tech pistons in my engine. The reason for this decision is based on the fact that during the past winter I was told by Clark's that forged pistons were not available and may never be available again! I felt at the time that I only had one way to go, now I know that forged are available but I am wanting to use the pistons I have installed. I know there are detonation concerns with the Hi-Tech pistons, but I thought to manage the risk I would slightly retard the timing and only use 100LL fuel. Do you think these precautions would be adequate ? I know that you are no fan of eutectic (sp) pistons but they must be better than cast, correct? Let me know your thoughts. If you think it is a very poor decision for me to use them I will defer to your judgement and save for the forged pistons. Thanks for your time,

    Ted Phillips, GN-1, Chariton, Iowa, tedanddj@mchsi.com
    Reply from WW:
    You will not get an ass chewing from me. Although I grew up in a U.S. military family, I believe it's a myth that military fathers teach their sons how to deliver first class ass chewings. All you'll get from me is the benefit of my knowledge and wise counsel. The decisions, as always, are all yours.
    Hypereutectic pistons are cast pistons. There are only three ways to make pistons: forge them, machine them from a billet, or cast them. A hypereutectic piston is a special version of a cast piston. While they're better than original cast pistons, they're still substandard to forged pistons for flight purposes. I cannot recommend that you fly hypereutectic pistons because I've never flown them myself. But, I do believe you could fly them on 100ll with reduced timing and careful attention to CHT, etc. But this is far from a ringing endorsement or a blanket approval. Now that the TRW pistons are back in stock, you always have the option of changing the ones in your motor out for forged pistons. BTW, I'm sure that TRW pistons are cheaper than hypereutectics. I don't think you'd have the same margin of safety with hypereutectics that you do with forged. The decision is yours to make.

    Subj: Skystar Series 7
    Date: 8/22/03

    Your feedback service is one of the best I've seen. Answering all these questions would drive me nuts, especially the redundant ones.-- Here's another one. Will the Corvair engine work in the Kitfox Series 7 by Skystar? If so, can we get the 125Hp I'd like to run?

    May God continue to bless you with an abundance of patience :-)

    Russ, rspmaggio@msn.com
    Reply from WW:
    A 3,100cc Corvair motor will deliver the kind of power you're expecting, and is among the lowest weight engines in this power category. But of course the biggest advantage would be the fact that such a motor could be built for about $4,000 in parts and a satisfying investment in time.

    Subj: 65 110 RB engine
    Date: 8/21/03

    Hi. Is a '65 110 engine with an RB code suitable for conversion? It is not listed in your Manual one way or the other, but the Corvair Underground book lists it as a "manual trans" the same as RA, another code you do not recommend. Am I to assume it has the same low compression heads?

    Max Marshall, Manual #5615, byteajoern@webtv.net
    Reply from WW:
    The reason why RB letter coded engines aren't in the Conversion Manual is that they're 140hp 4-carburetor engines. However, if you have the bottom half of one of these engines, it is perfectly suitable for conversion to a flight engine following the practices outlined in the Manual. You will just need a set of acceptable cylinder heads. Likewise, an RA motor can always have the bottom end used, but the cylinder heads have to be verified to ensure they are correct. Many RAs came with cylinder heads which end in the digits 0708 - these are not acceptable heads, but they interchange with plenty of other sets that are.

    Subj: Corvair Jugs
    Date: 8/20/03

    Just got my jugs back from Clark's; they were able to hone them out and keep them stock. I also ordered a set of long skirt pistons (they only have about 7 pistons left) and I'm awaiting the arrival of my Safety Shaft that I ordered from you a couple of days ago to get my crank tapped. Before I bore you with my happiness, I was wanting to know how much it would cost me for you to make me an engine mount for my KR2S and what information you would need to make it? I'm making it a taildragger.

    Last thing: The gentleman from Indiana who was at Sun 'N Fun when I had my case there and we removed the studs, I think his last name was Hudson. Do you have a good e-mail address on him? I would like to see his finished product. Thanks for all you and Grace and the bunch do for all of us...

    Bob Glidden, KR2S N181FW, glidden@ccrtc.com
    Reply from WW:
    There's a picture of Larry Hudson, his son Cody and the motor on display at Brodhead at the News from The Corvair Authority page on www.FlyCorvair.com. The Hudsons did a very nice job on their engine. Larry's e-mail address is indyannie_1999@yahoo.com.
    I have a jig to make motor mounts for the KR2 and KR2S. As long as your fuselage has a firewall with the same vertical dimensions as the plans, my mount will work with it. The taildragger version is $450 + S&H. The tricycle gear version costs $500 + S&H.

    Subj: I'm interested in converting
    Date: 8/19/03

    I apologize if the answers are in your Manual, but these questions come to my mind when trying to decide to have a go at building an engine based on your Manual.

  • I am technically savvy but own no specialized equipment. What investment in tools is required to be able to do a Corvair engine conversion?
  • Does your Manual start off with some guidelines on what engine to start with? It seems one must pay attention to serial number or model/year in order to have a successful conversion.
  • The 120 HP engine has a larger bore. Is there any info on how that is obtained? Is the standard engine bored out (seems like a lot of metal has to go) or do you purchase new cylinders/heads? Where does one get pistons? I assume the larger bore can work with the regular valves because the lower rpm (compared to automotive use) gives the engine enough time to suck the extra air in?
  • JP, jspeyart@pi.net
    Reply from WW:
    The majority of my customers are first time engine builders. The engine does not require any special tools. Perhaps a $30 beam type torque wrench from Sears is the only thing beyond wrenches and sockets. It certainly doesn't require a lathe, milling machine or anything like that.
    The Conversion Manual contains all the information you need to know about how to choose an engine: all the casting, stamping numbers, etc. It's available for $59 in the U.S., and $74 for international orders, including Canada, payable by check or money order in US Dollars to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the www.FlyCorvair.com Online Catalog.
    More info is in the Manual, but in a nutshell, the 120hp engine is made by putting 94mm VW cylinders and pistons on the Corvair motor. The machine work required is provided at a very modest cost by the man who offers the kit to do this modification. Your assumption about valve sizing is quite correct, also.

    Subj: Candidate Engine
    Date: 8/18/03

    I've run across another candidate engine through a member of a Corvair club. The owner has sent me a couple of photos that I was hoping you would look at and render your opinion. The seller says it's a 1967 110 HP engine. He acquired it from someone in Georgia and has had it in storage for the past 12 years. Prior to that I have no history. He claims the crank turns freely and that the matching heads are #3878566. Asking price is $150.00 OBO. I notice it does not have the Harmonic Balancer. I am suspicious about the block serial number. It almost appears as it has been re-stamped and that the original numbers are barely noticeable just underneath the current numbers. Just my imagination? I intend to look at it next week and will ask to pull the top cover off so I can inspect the crank. Any comments or advice is always appreciated, Thanks for your time,

    Ron Franck, franck@geneseo.net
    Reply from WW:
    Your plan to take off the top cover and look for 8409 on the crank is a good one. Judging from your information, I suspect the motor is a 1967 110hp. Some of these engines did not have balancers from the factory. I owned a 1967 Monza with this exact engine; it had never been touched when I got it, and yet it had no balancer. GM did some odd things the last three years of production. Let us know how it turns out.

    Subj: Preceptor for Corvair
    Date: 8/17/03

    I have gone thru your list & haven't seen anyone ask this question: Has anyone tried a Corvair in a Preceptor Pup (2 place)?

    Doug Baird, DBaird@barroncollier.com
    Reply from WW:
    I do not believe anybody has done that particular combination yet. I remember that Ultrapups were equipped with full VW engines, but I have no knowledge of what the upper limit of weight or hp is for your bird. The Corvair would certainly have enough power for a very impressive installation if the engine met the airframe's design specs.

    Subj: Turbo Corvair
    Date: 8/16/03

    For several months, I've eagerly awaited your article on turboing the Corvair to appear in the Summer issue of The Corvair Flyer. This is of very great interest to me, and I am sure, to many others. What happened? I have no doubt at all that your plate is very full; however, please let me and others know what the status of your turbo project is. Even preliminary information would be much appreciated. Thanks,

    G. Andris Vaskis, Westminster, Md., vaskis@gte.net
    Reply from WW:
    Yes, you're quite correct that the plate is very full. The turbo motor is essentially done. The work was interrupted by Oshkosh, but we are back on track. We have an airframe lined up to fly it on in the Fall after we run it on the test stand. I'm not sure, but we may get it running on the test stand before we send out the next Corvair Flyer newsletter. Be assured that it's of a personal interest for me to get it done, and that there are no technical difficulties standing between me and success, just a matter of getting a few more hours in here and there to get the engine ready for the stand.

    Subj: 88mm VW pistons/cylinders
    Date: 8/15/03

    Hi William:

    I have reported to my group (3 builders) our meeting at OSH. All the information you gave me was shared with them.

    If you remember, I told you that one of our buddies does want to use the VW 88mm cylinder-piston produced down here by Mahle. Although I respect him in this regard, I'm trying to talk him away from this approach because I think this will represent messing too much with the engine by introducing non-original parts in it. Nevertheless, I told him I would contact you in order to know exactly what would be involved in this.

  • The 88mm pistons would require him to rebore the case?
  • You told me the VW piston pins do not match the bore in the rod, and that the rod should be re-bored. Is this very specialized work, or something a good machinist would do?
  • Is there any other work to be done in the rod beyond that?
  • I suppose some work has to be done in the heads also to accommodate the new dimensions. Is that so?

    Any other thoughts? Best Regards,

  • Oswaldo, KR2, Rio, Brazil
    Reply from WW:
    The 88mm VW pistons and cylinders require no machine work to the case or the heads. Only the 94mm cylinders do. I consulted with Jeff at SC Performance to make sure that the 88mms would be dimensionally identical to the Corvair motor in height, etc., to make the engine a bolt together kit. If your friend wants to use the 88mm combination, Jeff will redo the rods to the VW pin size for $50. This is in addition to his regular $200 for rebuilt rods. He also has the $300 rod set which has polished beams. There are valid reasons to be attracted to both the stock pistons and the 88s. Neither one changes the fact that the conversion is a very simple one.

    Subj: New inquizator
    Date: 8/14/03

    Hi William. Until I saw the Corvair conversion at the Great Plains booth at AirVenture this year, I thought the AeroVee was the best value on earth. Now I know that's still true up to 80HP. But the Corvair looks like a very serious engine up to 120HP. At that HP, I'm wondering about altitude. Did I read that you're investigating turbo-normalizing the Corvair? Seems like a Q2 or the new Vision2 could really redefine the envelope if they could get above weather at speed. Please let me know what you're up to w/turbo.

    Joe Tocci, EAA Chapter 2, Fort Wayne, Ind., chairman@smdfund.org
    Reply from WW:
    Thank you for your nice e-mail. A few clarifications are in order. Great Plains is the VW outfit run by our friend Steve Bennett. He has nothing to do with Corvairs. You probably saw the Corvair motor on display at the Contact! magazine booth, around the corner from Steve. It's easy to get sensory overload at The Big O.
    My turbo engine is almost ready to run, and we'll post more information on the Web site soon. It's actually not turbo normalizing, but rather a turbo boost system. And its performance will decay at altitude. Turbo normalizing requires in-flight adjustable props. My intention is to come up with a very simple system that will retain 100hp at 10,000 feet. A Q2 does not have room under the cowl for a turbo Corvair motor, but you're quite right that a Vision EX is a good match. We'll keep you posted with a synopsis at the News from The Corvair Authority page on www.FlyCorvair.com, and also in greater depth in The Corvair Flyer newsletter.

    Subj: Head Studs
    Date: 8/13/03

    William & Grace,

    It was a thrill to meet you at the Contact! magazine booth and to participate in your engine seminar at Oshkosh. I have not yet contacted Clark's about the dragging OT-10 cam, but will do so tomorrow morning. I need seven (7) upper studs and two (2) lower studs. All of the case threads look good except for two, which have two partially broken threads. Would you confirm that ANY sign of broken threads require helicoil? In a couple of months, I will be needing a distributor rebuild and exhaust stubs.

    Joseph Snow, Brookville, Ohio, 1flashq@ameritech.net
    Reply from WW:
    It was great to meet you at Oshkosh as well. Yes, any sign of broken threads requires a helicoil. Please let us know if you still need the studs. I have used studs in good condition for $4 each payable by check or money order to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802. This includes the S&H in the U.S.

    Subj: Which Corvair Engines?
    Date: 8/12/03

    Hello, I attended your seminar at Oshkosh (I was the guy with his young son - in case you remember) and was very interested. You said there was some group that sold engines as opposed to finding one in a junkyard. What is their Web address? I just bought a partially completed KR2S kit and although I won't need a motor for a while, I will eventually need one and I want to start learning about it. When the time comes, I fully intend to take you up on your offer and come to your place for a class. Anyway, hopefully we can work together in the future. Thanks.

    Ray, KR2S, ray_pilot@yahoo.com
    Reply from WW:
    The Corvair Society of America, www.corvair.org, is who you're looking for. If you do not already have my Conversion Manual, I highly suggest you get it before acquiring a core motor. Every week, somebody buys the motor first, then tells me they spent too much money acquiring the wrong motor. All the part numbers, castings and stampings for the correct motors, along with how we evaluate them, are contained in the Manual. The Manual costs $59 in the U.S., $74 for international orders, including Canada. You can either send a check or money order payable in U.S. Dollars to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or pay for the Manual by credit card via PayPal at the FlyCorvair.com Online Catalog.

    Subj: VW 88mm pistons/cylinders
    Date: 8/11/03

    At AirVenture, you mentioned that, given the dearth of forged TRW pistons, the VW 88mm pistons make an attractive alternative to the forged stock pistons/cylinders, particularly as regards their lower weight. I can find no reference to this substitution in the Manual, and would appreciate it if you could provide me with the details, e.g., part numbers, possible sources, modifications needed to the sheet metal flashings, etc. Perhaps you could put this in a mailer as an "addendum" to your Manual, or a column in your Corvair Flyer newsletter (which I just subscribed to, so I apologize if you've already done that), or in your Q&A column.

    Don Lawrence, Los Angeles, Calif., don.lawrence@comcast.net
    Reply from WW:
    The TRW pistons are now in stock at Larry's Corvair Parts (phone # in your Conversion Manual). If you're still interested in the VW pistons and cylinders, the only source that I deal with on these kits is SC Performance. As stated in the Manual, Bob Sutcliffe developed these conversions. Bob has since sold his business to the very capable Jeff Ballard in Ventura, Calif. His phone number is 805 644-0006. Specific information about piston and cylinder combinations was covered in The Corvair Flyer just before you subscribed. New subscribers can obtain all the back issues as a collection for $10 in the U.S., $15 for international orders, including CANADA, payable only by check or money order for U.S. Dollars to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802.
    My Engine Assembly Video Part II, which will be available next month, has good visual comparisons of all piston/cylinder combinations for Corvair flight engines. Our friend Merrill Isaacson, aka SkyManta, a video wizard, is in final editing on these now. He is the production talent behind my other videos, as well. Look for Part II coming soon to the Online Catalog of Parts Available from The Corvair Authority.

    Subj: Sonerai Pics
    Date: 8/10/03

    Here are some better pictures of the Sonerai. About 60 hours now.

    Glen David, Indiana, propellerprecision@hotmail.com

    Reply from WW:
    Congratulations. The aircraft looks excellent. Please send us flight data when you get a chance.

    Subj: Upside Down Vair
    Date: 8/9/03

    Will the Vair fly inverted? Just in case my bird wanted to go inverted with me in it that is?

    John Foreman, Sonex #564, jwf3@daimlerchrysler.com
    Reply from WW:
    There's two ways to fly inverted: pulling positive Gs, such as the top of a loop, and true inverted flight, such as flying upside down in level flight. A Corvair motor, like all other aircraft engines, can do the first. In a maneuver like this, the engine and systems have no idea they're inverted in relation to the ground. In the second situation, you need inverted fuel and oil systems. 99% of aircraft engines, including certified engines, cannot do this. Only aerobatic airplanes like Pitts biplanes and Decathlons have oil systems which function with the airplane inverted. Having done a small amount of flying like this, I can assure you that the weak link is the pilot. Very few people are qualified to fly outside maneuvers and it takes a lot of training and physical strength to be safe and proficient.

    Subj: Thrust bearing
    Date: 8/8/03

    I attended your forum at Oshkosh and I must say I was impressed with your enthusiasm and dedication. I am unwinding from my trip as I expect you are, so I will try to phrase a yes or no question. I raised the question at your forum and you gave a good answer. A little fog has now settled but I think you said the thrust is taken at the opposite end of the crank from the prop hub. Are there any future plans to attach the prop to the transmission end?

    Danny, dannyjoe@insightbb.com
    Reply from WW:
    Good to hear from you. We just got back last night. We had a very good trip and really enjoyed sharing what we know with people who can use it. This is what it is all about. The thrust bearing is on the dirstibutor end of the Corvair. This is at the back bumper in the car, or a firewall in the plane. The Corvair is and has always been driven off the transmission end of the engine.

    Subj: Zenair twin, 100ll
    Date: 8/7/03

    I greatly enjoyed my visit to your Web site. The information put forth was very informative and rang of real world experience. I currently own a '66 Cherokee 180 C, but have the homebuilt bug biting me on the butt. I am trying to decide what airplane/engine I want to build/use and I appreciate the information. I owned a '65 Corvair Monza as a teenager and have always regretted selling it. Spent a lot of money at Clark's....

    I have been waiting on Zenith to develop the 620 twin. They are recommending Jabiru engines but I was thinking either Suby or Corvair. Your words of wisdom have been helpful. Do you believe that there will be any issues with the engine when 100LL is phased out in a few years? Thanks,
    Ronnie Jones, jones_rl@sbcglobal.net
    Reply from WW:
    I spent a lot of time with the Heinz family at Oshkosh. They're having a lot of success with the 601XL and expect it to be a major player in the pending Sport Pilot category. Their twin might be a lower priority project these days. I saw the plane in person several years ago, and it was very interesting. I'm not sure it was intended for engines any heavier than the feathery light Jabiru 80hp.
    I've operated the Corvair motor on both 100ll and auto gas. It works on either. Specific details of operational settings for both fuels are contained in my Conversion Manual, available at the Online Catalog.

    Subj: Zodiac 601 Mount
    Date: 8/6/03

    I saw in your answer to Neil Hulin's e-mail on the "Ask The Authority!" page that the 601 is one of the best candidates for your upcoming turbo installation. I am seriously considering matching my future Corvair engine up with a Zodiac XL. Will your install be on an XL? If not, which 601? Also, tell me more about your "turbo" engine. Thanks,

    Gary Kaplan, Zodiac 601, Mount Juliet, Tenn., Kaplan@qualityind.com
    Reply from WW:
    Yes, the 601 and the Corvair are a very good match. At Oshkosh, we spent a lot of time with the Heinz family, and they pointed out that the firewall bolt pattern has been the same on all 601 models for a long time. Thus, my work with Neil Hulin and others on 601XL projects applies to the previous models as well.
    The 601 has enough room in the engine compartment to install a turbo without crowding things too much. While it isn't needed to have good performance on the 601, the turbo is an interesting potential option. The XL has a 180mph Vne. A turbo motor at medium altitude (8,000-12,000 feet) would really make this airplane scoot. The high Vne is important because Vne is based on true airspeed, not indicated. If the Vne of the airplane was low, say 140mph, even a modest turbo Corvair motor could exceed this at altitude.
    I'll have more information on my turbo testing in the next Corvair Flyer newsletter.

    Subj: Vacuum pump
    Date: 8/5/03

    I caught your forum at AirVenture and had a question which didn't spring to mind until the drive home. Anyway, here goes: Do you know of anyone using an engine driven vacuum pump with a Corvair powered aircraft? Thanks for a very informative forum.

    Bryan Bowlsbey, R70BWB1@wpo.cso.niu.edu
    Reply from WW:
    No one that I know of, but many people are using belt driven pumps, and such an installation would be fairly easy on a Corvair. Everyone I can think of is using electric gyros.

    Subj: Stromberg carb
    Date: 8/4/03

    I hope you had a great time at AirVentures 2003! I need some info on the Stromberg carb. I've got a C-90 carb, but the previous owner says it leaks and no matter how many rebuild kits he uses, it still leaks. Is there a company that can rebuild the unit for me - and hopefully do it correctly? The project may hinge on the carb. Semper Fi,

    Dan Edwards, Dragonfly, newtonsrun@msn.com
    Reply from WW:
    A conservative estimate from Oshkosh would be 500 planes on the field with this exact carburetor. I did not notice any of them leaking fuel on the ground. This suggests the chances are excellent that your carb can be made to behave. Pat Panzera had a good source for needles and seats, but first check to make sure the float height is not ridiculously high. The rubber tipped needles in these carbs seal very well, but may be incompatible with auto fuel. A little careful homework here should yield you an excellent carburetor.

    Subj: Piston skirts
    Date: 8/3/03

    What is the difference in the long skirt TRW pistons and the short skirt? I know the long skirt are 1/2" longer, but is there that much difference in weight? And would it be ok to use the long skirts? Thank you in advance.

    Bob Glidden, Manual # 5471, glidden@ccrtc.com
    Reply from WW:
    The long skirts will work as a set. Our application is low rpm. Short skirts are usually aimed at higher rpm applications. The past few years of TRW production have been short skirts and these work fine. But, there was nothing wrong with the previous pistons. They weigh slightly more, but the strength of ARP rod bolts negates this difference. The only issue is that you cannot mix long and short skirts in the same engine.

    Subj: CH 701
    Date: 8/2/03

    I hope you are well. I have made my choice: The Corvair and the 701 are the only combo that make any sense in my world. So how can I make this work? Am I to be left out when hundreds of 701s are in the air with other heavy auto powerplants? Am I missing something here? Why have the Gods of aviation vexed me so? Is there any hope? Thanks,

    Steve Harmon, Ohio, iceman2@sbcglobal.net
    Reply from WW:
    Don't think of it as the gods vexing you. Rather, they are giving you an opportunity to show just how devoted to aviation you are. If you won the lottery, bought a turboprop Malibu and had a supermodel wife who also was a pilot, you'd probably fly a lot, but this would prove nothing of your devotion and love. In your situation, where you face adversity, hardship and moments of frustration, all under fiscal constraint, when you eventually triumph, the gods will reward you with many hours of wonderful flights because you proved worthy and only cursed them under your breath in moments of real frustration. The Heinz family reiterated their position that they do not like engines over 200 pounds on the 701. I seriously doubt that hundreds have flown with motors above this weight. The number is probably close to two dozen or so. Obviously it could be done, but the Heinzes do not encourage it.

    Subj: Crank case vent
    Date: 8/1/03

    Great site! Thanks for taking the effort needed to supply this great info!

    I have noticed that you offer a top cover to replace the stock cover with the fan bearing on it. Do you vent the crank case anywhere? There is a vent on the stock cover is there not? Is a vent needed and if so where/how is that done with your cover? Thanks in advance.
    Brandon, brandon@jdhgroup.com
    Reply from WW:
    Through much experimentation and testing, I've found the best place to vent the engine is through one of the valve covers. There is a lot less oil thrown around in the valve cover and a simple Cessna 150 air/oil separator does the job. This leaves the top cover free to be a simple sheet and greatly simplifies front starter mounting.

    Subj: Serial number, heads
    Date: 7/31/03

    I cannot find a listing for a Corvair with the serial number ending in RB. Also, how do I identify types of heads? I have found four in a wrecking yard, but no engines...they might be usable for aircraft use and then again they may not be....by the way, I bought manual #5441 from you...

    Bob, rwbtoy@fireserve.net
    Reply from WW:
    I don't have to check the book on the RB code. It is a 1965-66 164cid, 140hp motor for a high performance Corsa model. I know this because my land based Corvair is an RB coded 1966 Corsa convertible. Corsas only came with manual transmissions, so you have no worries about the retarded cam gear which came on 140 motors with auto transmissions.
    Everything on this motor is good for rebuilding and flying except the heads. The crank is the same 8409 forging, but it is nitrided, a small plus. Just get a set of '65-69 95 or 110hp heads and you're in business. Note that the old 140 heads should bring $200 on eBay, more if you have the linkage and carbs. The heads you need are worth half of this. A Corvair car collector would swap you heads in a heartbeat. Let me know what you find.

    Subj: Corvair Power 4 Gyro
    Date: 7/30/03

    I want a SMOOTH reliable engine (that does NOT sound like a snowmobile) for a tandem gyro...probably Air Command here in Texas. Operational weight of ship should be around 1200 lbs. Subaru is too complex. Do you think Corvair is a realistic solution? Regards,

    Charley, thejones@ev1.net
    Reply from WW:
    Gyros are not my field of expertise, but I listen to people who know them well, and I think the combo will work. The Corvair has a double-sided thrust bearing and is a proven pusher engine (its thrust bearing was designed to work in this direction). A smaller diameter prop on the motor, typical of gyros, will be an advantage to the Corvair; it builds HP faster than prop efficiency declines for a net increase in thrust. It is simplicity defined, and no aircraft powerplant can compete on a cost basis. This said, it also has a very nice note to the ear, which leaves two-stroke and four-cylinder guys a little envious. Let us know how we can help.

    Subj: T-51
    Date: 7/29/03

    I was reading about the T-51 produced by Titan Aircraft (Ohio). What are your thoughts on a Corvair for this aircraft?

    Jim Rogers, Mena, Ariz., docuome@msn.com
    Reply from WW:
    I've seen this aircraft in person and it is a beautifully made, light weight, kit. Although its performance may put it in the Sport Pilot category, it's not likely to be eligible because the category proposal includes only fixed gear airplanes.
    A while back, I had someone else inquire about putting a Corvair on this airplane. The response from Titan indicated that the aircraft is so specifically engineered for the Rotax engine that it would be very difficult, to say the least, to install other engines. Also, the kit carries a very high price tag. There are a number of other high end kits much more suitable to the Corvair. But, I understand your attraction to this beautiful airplane.

    Subj: Rings Question
    Date: 7/28/03

    After scouring the Manual for information on rings, I see a moderate endorsement for chrome. In my exchanges with Larry S., I'm told he also has moly rings as well. Clark's seems to have two different finishes for their rebored cylinders, one of which is intended for moly. Do you have any input to offer on this issue?

    Clay "Hoppy" Hopperdietzel, Vision, Tomball, Texas, hoppy@houston.rr.com
    Reply from WW:
    I have flown all three major types: cast, chrome and moly. They all work. Most of the motors I build have chrome rings and standard wall finishes. Cast rings break in very fast, but are not as good at high operating temps. Moly can take a while to break in, especially if the first hours of operation are a lot of mild ground running. Chrome is sort of middle of the road, and they have proven themselves in some very harsh tests we have run.

    Subj: Complete motor
    Date: 7/27/03

    I'm in the process of building a Zodiac 601XL and have heard you may be able to supply a 100-110 HP engine. I live in Alberta, Canada. Can you pass on some costs, etc.

    Dave, Zodiac 601XL, Alberta, Canada, dnimigon@telusplanet.net
    Reply from WW:
    My primary business is teaching people how to, and assisting them with, building their own engines. You can learn more about this throughout my www.flycorvair.com Web site. Although it is not my primary focus, I do occasionally provide complete motors. That story is also on the Web site. Click on complete engines at the FlyCorvair.com Online Catalog. I'm doing a lot of work to develop the Zodiac 601 installation and make it as easy as possible for 601 builders. I've already made several motor mounts and have a very accurate jig in which to produce more. There are a few more items to work on specific to the 601 installation, such as a cowling and intake manifold. All of my other products are applicable to a 601. The bible of flying Corvair motors is my Conversion Manual, and either way you go, it's the starting point where every one of my customers begins.

    Subj: Correct Corvair engine for aircraft
    Date: 7/26/03

    I am going to go out and scout around the Memphis area for some corvair engine cores. Are there certain model numbers/years/serial numbers that are preferable or should be avoided at all costs? Thanks in advance,

    Rick Pellicciotti, rick.pellicciotti@fedex.com
    Reply from WW:
    You are looking for a 164cid motor, a 1964-69 110 or 95 model. My Conversion Manual, available at the Online Catalog, has about 10 pages on codes, castings, engine selection and where to find the best engines and what to pay for them. Every month we get a letter from a guy who was looking at worn out Continentals for $4,500 and then got a "deal" spending only $900 on a 1962 Corvair, and now that he's got the Corvair, he wants a Conversion Manual. 1962 motors are the wrong year and they are worth less than $50. Please send me the letter codes before you buy anything, or you can get the Manual from us. Do not pay any more than $300 for a motor.

    Subj: Corvair Conversion Manual, 2002 Edition
    Date: 7/25/03

    I want to buy Corvair Conversion Manual, 2002 Edition. Can I send you cash through your postal address, and then you send me my copy?

    And I have a question... This is my first time to even think of building my own engine, is it kind of possible to make it happen without any help other than the Conversion Manual? Sincerely,
    Mulusew B., doilicho@hotmail.com
    Reply from WW:
    A number of first time engine builders have completed Corvair motors by studying my Manual closely and doing the work as outlined. Keep in mind I encourage builders to e-mail with questions as often as they like. If you are in the U.S., the Manual is $59, and outside the U.S. there's a $15 international S&H fee for a total of $74 payable in USD to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802. Most of our builders are first time engine builders. I've noticed that first timers read the directions with greater attention than people with experience who feel they don't have to pay as much attention.

    Subj: Vision Personal Corvair Cruiser
    Date: 7/24/03

    Hi guys. Here attached are the photos William took of Morgan. Enjoy!

    Grace Ellen, FlyCorvair.com Ask The Authority

    Reply from: Steve Rahm, Vision001@VisionAircraft.com
    Thanks, I'll get some of them on the site. Have a great trip!!

    Steve, Vison Personal Cruiser

    Subj: Prop Spinners, Flying Piet
    Date: 7/23/03

    Thanks for the "Corvair Flyer" in the mail ... it's a great publication. I'm very interested in the front spinner plate that you come up with for wood props using the Van's 13" spinner. I'll buy one when you get them ready!

    Another Piet is soon to fly on Corvair power... Carl Loar's stock Piet with a very plain-Jane 164 CID. I'll let you know when he does his first flight and see if he gets some photos. He's just completed weight & balance so it won't be long.
    Oscar Zuniga, San Antonio, Texas, taildrags@hotmail.com, www.flysquirrel.net
    Reply from WW:
    Good to hear from you. Please encourage Carl to contact me. A number of guys somehow figure they don't want to bother me before their first flight. I'd gladly spend an hour on the phone going over a checklist of items with anybody. Although it's all in the Manual, invariably in conversation I can find something that was left undone.
    I'll put a post on the FlyCorvair.com Online Catalog when I have the front spinner plates available.

    Subj: CG
    Date: 7/22/03

    Hope Oshkosh treats you right. Wish I could be there. Question: Where is the CG located for your engine conversion with the front starter? Weight should be considered to be right around 225 lbs. for weight and balance calculations? Thanks.

    Oscar Lind, Seattle, Wash., oscar@waggonerguide.com
    Reply from WW:
    Depending on a number of small factors, the exact CG location is variable. But, you can get a pretty accurate calculation figuring the CG to be in line with the #4 sparkplug.
    225 represents the engine with the oil in it and the systems to run it. Mounts weigh 5-6 pounds, props are in the 5-10 pound range.

    Subj: Murhpy Rebel/Corvair
    Date: 7/21/03

    I have been considering a Murphy Rebel as a project, but have been put off a bit by the cost of the 912s and 235s that they recommend. Now, after reading through your Web site, am I seeing a viable alternative in a Corvair engine? I have always had very good luck with them (a VW conversion and a Porsche 356 conversion back in the '70s ). I never had any problems with those engines at all ! I'm not fully versed yet in all the math needed to figure this all out, but I can build one of those motors. What do you think?

    Allan Nelson, Seattle, Wash., allan@wattsrv.com
    Reply from WW:
    I have always liked the Rebel since it came out 10 or 12 years ago. Your positive experience is typical of people who have actually worked with Corvair engines. I am sure the Rebel can be suscessfully powered by a Corvair.

    Subj: Zenair 601 Motor Mount
    Date: 7/20/03

    I'm writing to confirm that you propose to use the 38mm long x 3/8 ID washer and welded tube firewall attachment depicted in the lower centre of diagram 6-YE-2 that I provided to you. The original engine mount fittings that mate with the mount attach points have the short bolt for the Jabiru mount. I'm getting the O-235 mount fittings from Nick @ Zenith and will be installing those in the next week or so unless you tell me otherwise.

    Neil Hulin, Zenair 601, Cincinnati, Ohio, nhulin@hotmail.com

    Reply from WW:
    I thought I'd post a photograph of your new motor mount. Also in the above photo is my 601 Corvair Motor Mount Jig. As you noted, it shares the same fuselage mounting points as the 235 installation.

    The mount weighs 6 pounds on the nose. It turns out, after careful calculation, the Corvair's prop flange will be 2" ahead of where the 235's is. This is mandated by the fact that the Corvair is a significantly lighter engine. Because the Corvair has no mags on the back, there is a generous amount of room in the engine compartment which always makes for an easier installation. The 601 and the Vision have this space in common, and are the best candidates for my upcoming turbo installation.

    Although I'm very busy, I'm planning on bringing your mount and one other 601 mount to Oshkosh. If anyone out there would like to bring the second mount home and save on the shipping, send an e-mail to WilliamTCA@aol.com and let me know.

    Subj: Starter Kits
    Date: 7/19/03

    Do you still have the starter kits available? If so, what is today's price and do you take PayPal for that like the rest of the stuff?

    David Voit, Vision Corvair Cruiser, Lodi, Calif., dvoit@pacbell.net

    Reply from WW:
    We're getting a big batch of stuff ready for Oshkosh and Starter Kits are one of the things we are boxing up. They will appear on the FlyCorvair.com Online Catalog with a PayPal button in a few days. I will send you a note as soon as it does. We will have a discount for Corvair Flyer subscribers also. You will see that in your mailbox in a few days as we mailed out hundreds of copies of the Summer 2003 issue today.

    I built a jig for the Vision Corvair Cruiser motor mount two days ago and spent most of the day welding up Cruiser Motor Mount #1. A very rigid and compact design. The photo above shows three of my motor mount jigs. The orange one is the Cruiser jig, the green one is my well used KR2-KR2S jig, and the black one is for the Zenair 601. We'll post a photo of the Cruiser mount on the plane here on the Q&A in a few days.

    Be glad to make you a motor mount whenever you're ready. At lunch I sat down and figured out that this was the 17th different Corvair motor mount design I have done. Some, like my KR-2, have sold more copies than I could remember.

    Subj: ENGINE HOURS
    Date: 7/18/03

    I WENT THRU THE LOG BOOKS AFTER I GOT BACK AND THEY ADDED UP AS FOLLOWS:

    39.5 HOURS TOTAL 18.5 HOURS IN FLIGHT

    THANKS FOR ALL THE HOSPITALITY. YOUR FRIEND,

    BOB LESTER, KR2, FORT LAUDERDALE, FLA., rel111901@aol.com

    Reply from WW:
    I got this quick note from Bob Lester and thought I'd share a photo of his Corvair powered KR2 leaving the runway at Spruce Creek for the 180 mile trip to Boca Raton, Fla. He had cruised up at 160mph at 6,000 feet. He said the engine was turning a little less than 3,000 rpm and the fuel burn was around 6 gph.

    Subj: Turbo Heads
    Date: 7/17/03

    My name is Guy Kelly and I purchased Manual #5608. I think it was Grace that included a note with it regarding a Guy Sillikers of Sunny Corner, N.B., Canada. Tell her that he is still alive at 85 and talks as much as ever. He lives 18 miles west of me.

    I have a Corvair that was modified about 25 years ago and never run. Problem is that it's a '63 turbo according to the block #T0119YR (head #3817287). Heads have been modified for dual plugs. Original centre plugged (threaded), two other machined one on each side of centre plug. Excellent workmanship. It has two distributors: the original and another on pulley end of crank by way of a bracket.

    Could you use these heads, and could I put a set of your 110 heads on this motor, or should I try to get another engine? Any info would be apreciated. Thanks.

    Guy Kelly, Miracmichi City, Canada, mammie@nb.sympatico.ca
    Reply from WW:
    Guy Sillikers was a big part of Grace's childhood. She enjoyed her months spent in Canada.

    The Conversion Manual contains a lot of good reasons why a 1964-69 engine is more desirable. But your engine is somewhat of an exception. A '63 turbo motor actually has the stronger crank material and stronger rods of the 1964-69 motor. The non-turbo 1960-63s did not have these features. Forged pistons will be a little difficult to find for the 145cid motor. But cylinder heads are dirt cheap for these engines, and I would highly recommend going back to a standard set of heads for it. Dual plugs in any Corvair head require a lot of cooling fin removal right where you need it the most. Let us know how it goes.

    Subj: Ultravair
    Date: 7/16/03

    Check this out ... what think you?

  • From: faburns@rockwellcollins.com
  • We plan on trailering the MiniMax to Oshkosh the weekend of the 26th of July and parking it in the ultralight area. Someone will be there with it throughout AirVenture. I will deliver it there the 26th or 27th then return home until Thursday the 31st, then I will stay there until the end. I had a lot of help from friends here at work and they will be there during the week too, but they would prefer it if I answered any technical questions. This engine has been in the back of my mind for years and with their help all the pieces finally came together.
  • Mary Jones, Experimenter Editor, Oshkosh, Wisc.

    Reply from WW:
    Interesting motor. I'm looking forward to seeing it in person. Fletcher Burns was one of my first customers to buy my Conversion Manual years ago and build a full Corvair motor. He is a clever guy and still holds the record for lowest price of a Corvair rebuild and conversion ($1,100). He is quite a scrounger and home machinist. He is an experienced builder - I know he built at least one plane, a Sonerai II.

    I looked at the photo for a few minutes and think he has got all the major points. It appears to have a cam drive VW oil pump, and I am curious as to what type of regulator he's got. He will have some new type of thrust bearing because the standard one is in the missing part of the motor. 80 pounds for it actually seems a touch high.

    I keep a lot of data on the Corvair, and I think he may well be the first guy to make a 1/3 Vair run. Several people built a 1/2 Vair inline three in the 1970s, but they are radically out of balance and have poor power to weight. If he has good solutions to the issues, he will change the landscape of the 1/2 VW world because Corvair stuff is very cheap and tough as nails by comparison. Power is going to be slightly less, because a 1/3 Corvair is only 900 to 1033cc, but most of the motors in the class have optimistic power claims.

    Technical Note from WW: Mary Jones, my boss at EAA Publications, forwarded the above message and photo to me. I thought people would like to see the photo. A few days ago, I answered an e-mail and said the Corvair is sort of an all or nothing affair in response to a guy trying to make a 3 or 4 cylinder engine out of it. Technically, the only reasonable possible combination is the full motor or an opposed twin like we see in the above photo. We'll get more information at Oshkosh and post it on FlyCorvair.com.

    Subj: Corvair in STOL aircraft
    Date: 7/15/03

    Several people, as well as myself, are interested in the Corvair engine in the Ragwing Stork, an 80 percent scale reproduction of the Fiesler Storch. There is currently a debate as to how effective the Corvair would be in STOL applications. What is your opinion on the Corvair as an engine in a STOL bird, such as the Stork?

    Drew, Ragwing Stork
    Reply from WW:
    I have received numerous inquiries on this subject. Let me take a few moments to address the general topic. Please share this with other builders who are considering the same type of installation.

    Please note that I've had no direct contact with Roger Mann. One of his builders gave me his phone number, but I've only spoken with his answering machine. Although we travel to airshows nationwide, I've never seen or met Roger. I bring this up because I've had numerous people share comments attributed to Roger that may have lost something in the translation.

    The primary concerns of an engine installation are weight and thrust. Although I have not seen what Roger's published limits are, I can honestly state this from converting many airframes to Corvair power: A standard Corvair engine installation weighs 35-40 pounds more than a direct drive VW Type I. It is lighter than a Subaru EA-81 with reduction by 25-50 pounds. It is very close to the same weight as an O-200. Modified Corvairs, such as the 190cid model, are 8 pounds lighter than the standard conversion. Specially built Corvairs have been made perhaps 10 pounds lighter still. But, the engines I will restrict my comments to are the standard Corvair models, which 90% of our engine builders are converting. This is the 164cid (2,700cc) electric start motor with no special attempt to lighten it.

    On the subject of thrust, there is a great degree of misunderstanding amongst homebuilders. Let me preface my remarks by saying I have a unique background in props, coming from Embry-Riddle Aeronautical University, having been the highest ranking U.S. employee for the esteemed company MT-Propeller, having been a dealer for many other types of props, and having owned, tested and flown many different propellers. I believe very few people making comments on the Internet could match my background on this.

    People always quote ridiculously high static thrust numbers and overemphasize the importance of diameter. If you would like a reality check on thrust numbers, Bob Barrows, the highly respected designer of the Bearhawk line of planes, thrust tested dozens of certified airplanes that came through his facility over the years. His Web site lists the exact engine make, model, prop, etc. If you study the data, you'll see that it takes something on the order of a 360cid 200hp Lycoming swinging a 72" diameter metal prop to generate 800 pounds of static thrust. This is why you should be very skeptical when people throw around numbers in the 600-700 pound range associated with 90-100cid engines.

    On the subject of diameter, consider this: Cessna built 15,000 150s with O-200s. Many people know that this airplane has an empty weight of 1,050 pounds or more and is a large aircraft by 2-seat homebuilt standards. Yet, these workhorses do all of their work on 69" diameter propellers. Cessna could have chosen any diameter prop they wanted, but 69" is their optimum diameter. It is a myth that there is an advantage to a 72" prop over one which is slightly smaller. If a Cessna 150 would have had even 150 feet per minute more rate of climb with a 72" prop, they would have put one on. The truth is, the engine made greater average thrust over a wide range of airspeeds with the 69" prop that is certified on the plane.

    Even if you're expecting much greater than 150 performance from your homebuilt, the point is that an O-200 does a very respectable job of powering an airplane as big as a 150 because it has a highly optimized propeller which stands in contrast to the 72" wives' tale.

    It is possible to get very high static thrust numbers by pitching the prop so low that its useful range of airspeeds might be below 60 mph. A lot of numbers are quoted this way. The same engine and prop diameter, pitched for an 85 to 90mph cruise, will have much lower, perhaps 30% less static thrust, but it will be a useful prop.

    We recently thrust tested a 72" Warp Drive on a Corvair without a cowling, and with a cast iron exhaust and big muffler in place. It pulled 385 pounds of thrust at 2700rpm at a pitch which would yield a cruise speed of 85 or 90mph, with a redline of 105 or 110. With a cowl and a flight exhaust, it would be 425 pounds or so. This combo would produce good average thrust over a wide range of airspeeds. In contrast, slow turning fixed pitch props are good performers at a much smaller range of airspeeds. In a contest from brake release, take off, climb to 500' and level flight to100mph, smart money bets on a setup like a Corvair or an O-200 over a smaller motor turning a heavily reduced prop.

    There is also the issue of cost. I am puzzled by designs which are labeled as "affordable," yet the designer wants you to use a motor which costs more than the airframe. Most of our customers are spending less than $3,000 total on their motors. This seems much more in line with the philosophy of plans built airplanes.

    Over the years, I have owned a tested a lot of different flight equipment. I do not comment on things I have not worked with myself. Last week a guy told me that a C-85 produced more thrust than a Corvair. I asked him if he had ever seen a Corvair turn a prop. His answer was no. I asked if he even owned or operated a C-85. He did not. I own both, and have built, flown and tested them. Some people are pretty bold about making statements of which they have no firsthand knowledge.

    I am giving 5 forums on engines at Oshkosh this year (schedule is posted at News from The Corvair Authority) . I will also be spending a lot of time at the Contact! magazine Booth 3109. I encourage anyone to come by and talk about motors and props. Be glad to share what I know.

    Subj: 601/Corvair Progress Report
    Date: 7/15/03

    I have purchased a 1968 95 HP (TA) engine, 164 CID and it has the correct heads on it, 3878569 with quench area. The interesting thing is that the engine has a "Torsional Vibration Dampener" on it, and I was told by the seller that the engine was never worked on to the degree that something like that would have been replaced. He claimed that the vibration dampener was stock because the car had air conditioning right from the factory(?).

    I will be checking the Web site frequently as your development of the "firewall forward" stuff for the CH601 may be where I'm headed.

    Thanks again for being "in the arena."

    Gerry Scampoli, Zenith 601, Manual # 5600, GScampoli@HomeMarketFoods.com
    Reply from WW:
    The last three years of Corvair production are famous for having a lot of minute variations. Years ago, I purchased a completely original RD code 110 engined 1967 Monza coupe. It had no harmonic balancer. Your experience may be similar to this. In any case, it doesn't matter because we know what we need for flying.

    I am bringing Neil Hulin's 601/Corvair motor mount with us to Oshkosh. I have several forums there (see the News from The Corvair Authority page for the full schedule), but I'll leave the engine mount on display at the Contact! magazine booth. I built a very stout and accurate jig for it. I am working from complete sets of factory drawings supplied by Neil, and the mount should bolt right up. It has correct offset, inclination and CG information for the Corvair.

    Subj: PFA Corvairs
    Date: 7/13/03

    We had a very successful day with our PFA Chief Engineer who was impressed and 'excited' by the Corvair! It was a very popular exhibit on our Pietenpol Club stand! You may be getting an enquiry from a fellow builder David Hanchet ref shipping a core over for him... Regards.

    Paul J. Shenton, Pietenpol, England

    Reply from WW:
    Glad to hear things are progressing in England with the PFA. Some people on this side of the pond often parrot the story that introducing new engines to the PFA is impossible. Your efforts on behalf of the Corvair obviously stand in contradiction to this. As always, progress in aviation is made by people in The Arena. Congratulations on your efforts so far.

    Subj: Forged pistons
    Date: 7/12/03

    Like many others, Iím having difficulty finding forged pistons. My machinist has bored my cylinders and they cleaned up at .060. Do you have or know anyone who might have a set of .060 forged pistons for sale at a reasonable price? Thanks,

    John Krumrine, Zodiac 601XL, College Park, Penn., jqk4@psu.edu
    Reply from WW:
    Please note that forged TRW pistons are back in production and the first batch will be on the shelf at Larry's Corvair Parts (phone number in my Corvair Conversion Manual) July 25. They are priced at $269 a set, and Larry says they will be available in all sizes. He is taking advance orders at this point. When you contact Larry's, please tell them you're an aircraft builder, as we're trying to get an idea of how high the percentage of forged piston buyers are aircraft guys.

    Subj: Corvair for Jodel D-18
    Date: 7/11/03

    I read and re-read all your very informative info.

    Dad was an A&P, and automotive instructor for trade schools and community schools, so reading and looking at your information to me is secound nature. ( Plenty of dining room conversations revolving around engines and transmisions! lol) And about 200 tranys rebuilt and 3 VW engines rebuilt under my belt, so I can imagine the time and work you have put into the Corvair.

    I have owned one certified plane (PA-16) w/O-235 engine and now have finally decided on building the Jodel D-18 as it's my estimate that it may be a strong candidate for the Corvair installation. Weight and balance seem to work out nicely. Do you have any personal information on this? Or comments? Thank you for all your efforts.

    Michael Pitman, Portland, Oregon
    Reply from WW:
    Jodels are well respected designs. For the models aimed at the 100hp category, it is a natural match. Perhaps the only drawback to a Jodel is its somewhat large one-piece spar, which presents a space challenge to some people building. But, its good qualities certainly outweigh minor drawbacks. A gentleman in our EAA chapter has one and raves about it. It certainly appears to be a nice flying plane.

    The Jodel's proven nature stands in contrast to a lot of new designs that crop up which generate a lot of interest, but to people working in the industry remain unproven. All aircraft, from the Wright Flyer to the 747, were unproven designs in the beginning. But the work of flight proving a design is the realm of the professional, not the sport pilot. There are actually a handful of new designs every year which are marketed to unsuspecting people who assume that the airplane is structurally sound and has been wrung out. Sadly, this is not always true. New builders have occasionally wasted a lot of time building an airplane which has never been reviewed in a magazine, flown to Oshkosh, taken on a significant flight, etc. For those who are new to aviation and building and are a low time pilot, I encourage you to build successful flight proven designs such as the Jodel.

    Subj: Oil cooler
    Date: 7/10/03

    Hope you remember me from Preston, Minn.; the can of Cherry Grove dirt? My Piet is ready to go, at least so I thought. I was doing high speed taxi and the oil temp rose to 280 degrees! I got out your Manual and ordered a folded fin cooler. Is this the right thing to do or should I install a remote cooler? My present oil cooler is an 8 fin. Also, where should the oil temp probe be located? It looks like mine is in the rear of the engine just above the oil pan. Hope to see you at Broadhead. Thanks.

    Dave Mensink, Pietenpol, Preston, Minn., dmensink@earthlink.net
    Reply from WW:
    We remember your hospitality well, and we still have our can of Cherry Grove dirt on the kitchen counter.

    A folded fin or twelve plate will be superior to the 8-plate by a mile. 280 degrees is too high. The cooler should make a difference. Also note that twice in the past year we've had two customer oil temp problems turn out to be faulty gauges reading high. Your Pietenpol style setup with the blower fan is particularly resistant to high temps. Please note there's several little sheet metal pieces that mate with the top shroud to ensure the air's directed over the cooler.

    See you at Brodhead.

    Subj: Dual Points Distributor
    Date: 7/9/03

    I purchased the Conversion Manual from you a few months ago and I have since noticed that there is a Mallory dual points distributor from Clark's. Is this similar to what you do when you rebuild one?

    Scott Laughlin, cookwithgas@hotmail.com
    Reply from WW:
    The Mallory is aimed at high rpm racing. It has only three lobes and each set of points runs half the motor. The idea was that the points wouldn't get worked as hard if the motor was spun to 7,000rpm. My setup uses a six-lobed cam to create redundant ignition. Since we turn less rpm than the car did, we have no problem with point life.

    Subj: The New Conversion
    Date: 7/8/03

    We finally got our engine running. It may need some more tweaking, but is not broken in by any means. We had a terrible time starting it (hand prop) until we had about an hour of ground running on it. The problem seemed to be the terrible strong drag on the cast Grant rings. It was so hard you couldn't tell when you were coming up on compression, but that is getting a lot better with every run. We are using the breakerless distributor set about 12 degrees initial and haven't gotten enough courage to try to see what kind of advance we are getting at full throttle. It turns 3,000rpm static and a little over on takeoff. First flight was today (about 15 minutes) and so will have to get some more time to get the readings finalized. Rich reported the airspeed read 85 at level flight and the GPS said 71mph over the ground. We think our oil temp is a little high and will be working on lowering it some. --240 degrees "F" at the filter. I don't think we have enough outlet on the bottom cowl so will open that several more square inches next. The John Deere Dynamo works great so far. We are not electrical engineers so don't know how long the "Goldwing Motorcycle" battery will take the 14.2 volts. I think it will depend on the amperage more than the voltage??

    We aren't going to make the Brodhead Pietenpol Fly-In. I (Ray) am an early Hatz builder, Serial No.#6 1981. Although I don't own it anymore, I'm pledged to attend the 35th year Hatz Reunion at Merrill, Wisc., that same weekend. I will attend the Grass Roots affair at Brodhead in September. Maybe Rich will fly the Pietenpol over there for his only cross country this summer.

    It has been a long and frustrating task rebuilding the Corvair but I hope it will prove to be worth the effort. The biggest problem we found was the baffling and the remote mount filter and cooler.

    Well as my old TWA captain buddy used to say, "Keep the oily side down and the shiny side up" and we will hope to see you some day at a Sport Plane Fly-In.

    Richard & Ray Hill, Pietenpol, raydot@pcpartner.net
    Reply from WW:
    Congratulations.

    It will get much looser, as I am sure you know. 240 is not too high if this is before the cooler. It will drop 20 or 30 degrees when the cylinder friction goes down. Generally this takes 2 to 5 hours.

    14.2 should be fine; check the water in the battery frequently, but this should not be too high.

    It may have been work, but if building and flying planes was easy, then everyone would do it. I am sure you know it was worth the effort.

    Subj: Metal Props
    Date: 7/7/03

    My name is Samuel and I'm building a Midget Mustang (MIA) from kit. The plane is designed for engines from C-85 CFJ with prop diameter of 58" up to 150hp engines as Mustang Aeronautics (maker of kit) publish. The Corvair engine is a good choice for me and I would like to know if it accepts metal propellers as well? Many thanks.

    Sam Tor, Midget Mustang, Israel, torsh@zahav.net.il
    Reply from WW:
    A good friend of mine has an 80% complete Midget Mustang. I just made a Corvair to MM mount for it two weeks ago. A picture of it is below. My friend has owned one before and thinks they are great planes.

    I do not aprove of metal props on Corvairs. Most people no longer fly fixed pitch metal props on things like Midget Mustangs because the speed of the plane requires the prop be pitched out of limits. People have been killed doing this, so the general thought is that wood props are the way to go. (Popular fast homebuilts like 360 powered RVs have special metal props made for them.)

    Subj: Ballast Resistor
    Date: 7/6/03

    Where does the ballast resistor fit into the ignition system?

    Fish Fischer, Dragonfly, Warrenton, Ore., fishhole@pacifier.com
    Reply from WW:
    A ballast resistor's purpose is to lower the 12 volt system voltage to the coil for continuous operation. Thus, it is in line, in the 12 volt line, to the positive side of the coil.

    Subj: Stromberg Carb
    Date: 7/5/03

    I have a question about the Stromberg carb. I have found one and the guy who is rebuilding it for me says that he is installing the large needle valve and that he has a venturi that looks as if it has been polished (?) and maybe about 40mm. My question is: Does this sound good for our application? I am thinking with the bigger venturi maybe I can feed the motor more fuel, i.e. more power. Yes -No? He says he is also setting it up for running with a fuel pump 2-4psi. I believe your Conversion Manual states that the stock pump runs about 5psi, so I will have to also run a regulator. If I am running a boost pump (Zodiac CH601 XL), will the stock fuel pump handle the extra pressure or should I run a fuel line from the boost pump to the carb bypassing the stock pump? Thanks for any help.

    Doug Cowlthorp, Zodiac CH601 XL, Winnipeg, Canada, thorp@escape.ca
    Reply from WW:
    If the venturi is actually 40mm, it's probably too big for a Corvair. The Corvair will run surprisingly well on carbs as small as 32mm, and in some cases we use 35s. But, if you do the math, a 40mm carb has a drastic increase in area that the Corvair does not need. Too big a carburetor sacrifices some desirable characteristics, such as accurate metering at WOT. A Corvair fuel pump is in the 5-6psi range. I have seen it run being fed by an electric fuel pump, but test your pump carefully. Many of them produce excessively high pressure and you would need a regulator. If you're interested in using the stock pump, perhaps you should look at an MA3 carb, as they handle fuel pressure naturally and come equipped with 35mm venturis.

    Subj: Corvair Powered SL-2 Project
    Date: 7/4/03

    I sent you an e-mail a couple weeks ago asking for Corvair engine information. Thank you for the reply. I will be getting the Conversion Manual and Corvair Flyer newsletter soon. I put together a Web site, http://geocities.com/davedpilot, to show what I've been working on. I will add more content as time allows. Check it out and link to it if you want. I put a link to flycorvair.com, if you don't mind. Thanks.

    Dave Goolsby, davedpilot@yahoo.com
    Reply from WW:
    Let me first say that you're an awesome CAD draftsman. The graphics are first rate and very eye pleasing. Secondly, your aircraft design has a very aesthetically pleasing shape to it. I'll be interested to see how it progresses for you. I have a number of people, both amateurs and professionals, working on designs specifically for the Corvair engine. The engine's affordable nature has certainly sparked a lot of creative interest. I showed your design to several people, and one relatively green guy said "Hey, that looks like a .... " so and so. About simultaneously, the experienced guys said, "Yes, all good aircraft designs bear a resemblance to another successful design." If anybody brings this up about your design, make sure you use the response of the professionals.

    Subj: 12-Cylinder Corvair
    Date: 7/3/03

    Could two Corvair engines be mounted in tandem or top and bottom to drive one prop and produce 200 + HP? One carb to feed both engines --12 cylinders !!!??? How is that for a WILD idea?

    Lynn Clark, Chappell, Neb., ilflyaw@megavision.com
    Reply from WW:
    I'm usually entertained by challenging ideas. I hear stories that many people in the business are always complaining about customers who have off the wall ideas. While we get the occasional question about putting a Corvair motor in a Lancair IV, for the most part, questions that are like yours are simply creative people exercising their imagination and I applaud this. I am certainly guilty of enjoying many a late night in the hangar with my mechanical friends and musing over such ideas. Anyone who doesn't enjoy this process is missing some of the fun. Keep in mind, though, actually building and flying some of these may be hazardous to your health. 200hp of Corvair engines would probably weigh 440 pounds. Even if they shared some items - starter, carb - it would still weigh 400 pounds for 200hp. Compared to many other automotive conversions which claim to produce 200hp, this would actually weigh less than things with radiators and cast iron blocks. As a reality check, a 360cid 200hp Lycoming has an all up weight in the neighborhood of 330 pounds. Keep up the imagineering.

    Subj: Corvair Engines on eBay
    Date: 7/2/03

    I came to your web-site from Vision Plane. Both sites gave me a push of adrenaline when thinking that I may no longer only dream of but really fly my plane! Congratulations for your perseverance and contribution to "everybody's flying pocket."

    Lately I've noticed that someone is selling several Corvair engines on the eBay. May I please have your advice about their feasibility to be overhauled and transformed into flying engines? Many thanks in advance.

    Sasha, sasha47@kornet.net
    Reply from WW:
    Thank you for your nice comments about my work. Vision aircraft are the products of my friend Steve Rahm. He is very devoted to the concept of keeping aviation simple and reasonably affordable, as am I.

    My Corvair Conversion Manual contains all the details on engine selection, head numbers, how to identify the parts, etc. It's available for $59 in the U.S. and $74 for international orders by credit card at the FlyCorvair.com Online Catalog or by check or money order in U.S. dollars payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802. But, basically you're looking for a 1964-69 95 or 110hp motor. Either one is a good start on building a 100hp aircraft conversion.

    Subj: Carb location
    Date: 7/1/03

    I've read your Manual cover to cover and find it very enlightening. It's refreshing to read about the real world instead of a lot of ill-informed arcticles from people who haven't gotten their hands dirty. Thank you. Question: How difficult would it be to move the carb forward to about mid-engine? The design I most want to build has a lot of structure under the back third or so of the O-200 powering it. I'd much rather power this aircraft with a Corvair. Do you have experience with the carb in other positions under the engine? Are you still as impressed with the Aerocarb? Many thanks.

    Oscar Lind, Seattle, Wash., oscar@waggonerguide.com
    Reply from WW:
    Thank you for the nice comments. The Corvair is not particularly sensitive to carburetor location. It makes its horsepower the old fashioned way, by cubic inches. I have tested countless carburetor locations, sizes and styles. The engine is a good performer with virtually any system that visually makes sense. The two features that are most counterintuitive are that the length of the tubing does not affect the horsepower output of the engine and that the engine will make its power on a smaller carburetor than would be required for the same power output in an engine with less cylinders. Our friend Steve Makish (see Steve Makish's Corvair Powered KR2 on FlyCorvair.com) is currently flying a Corvair powered KR with an Ellison throttle body in much the same location as you describe. The airplane has well over 100 hours of Corvair powered flight on it.

    Subj: RANS S-6 COYOTE
    Date: 6/30/03

    I've been spending much time on your Web site and am very interested in your Corvair engine. Do you think that it would be compatible with a Rans S-6S Coyote? The company recommends/sells any Rotax between the 582 to the 912S for the plane. The Rotax is about 40 lighter than the Corvair and that is without the electric starter. Any thoughts on this issue would be greatly appreciated. Thanks.

    Steve Hart, Bremerton, Wash., harts@psns.navy.mil
    Reply from WW:
    I have not studied the Rans designs closely as they rarely fly with alternative engines. A good starting point with an airframe designer is to ask him whether or not the particular design could be flown with an O-200. Almost all airplane designers are familiar with the O-200's size, weight and power characteristics, which are closely matched to the Corvair's. In my experience, many airplane designers, while masters of their art, are not well versed in alternative engines. Although we think of the Corvair as being very popular, many airframe designers do not have direct experience with them and certainly many of their opinions are based on old wives' tales about the engine. Phrasing the question about an O-200 will generally yield useful technical data without addressing an airframe designer's limited Corvair exposure.

    About once a week we get a letter from an airplane builder who says his airframe designer states that Corvair motors are either too heavy, don't make enough power, etc. In many cases, these designers could not answer fundamental questions such as how many cubic inches is a Corvair, how much does it weigh, or basically, have you ever seen one turn a propeller before. The majority of respected designers, when asked a question about a subject they're not well versed in, will simply say "I don't know much about it." Sometimes we deal with the reverse.

    Subj: Corvair-powered Junior Ace question
    Date: 6/29/03

    I'm deciding whether to build a Piet or a Junior Ace in my garage. If I were to use a Corvair engine in a Junior Ace, including an electric starter, could I safely keep the weight under the LSA limit of 1232 pounds?

    Mark Hodgson, mhodgson@bu.edu
    Reply from WW:
    Either airplane, Piet or Junior Ace, can be built with a full electric start Corvair and still retain an excellent useful load. There are many examples of Corvair-powered Pietenpols. If you'd like an example of a Corvair-powered Junior Ace, check out Jake Jaks' Web site, http://home.att.net/~jrjaks/index.html. Jake was the first graduate of Corvair College. Either of these aircraft are excellent performers on a Corvair motor, far exceeding their original performance on engines like 65 and 75hp Continentals which are now unaffordable, and never offered such conveniences as full electric starting.

    Subj: Corvair car carbs
    Date: 6/28/03

    I just happened to take a look at the Pietenpol and ended looking at your Web site on converting the Corvair engine for aircraft use. I have only one question: Can you use the original carb (the one used in the car) for aircraft use? Thanks.

    Dean, deanvoisine@yahoo.com
    Reply from WW:
    The Corvair cars have 2 or 4 downdraft carbs (depending on the model) bolted directly to the head. They are 4" tall and would be impossible to streamline into a cowl.

    Subj: Carb, safety shaft, prop
    Date: 6/27/03

    I have started conversion of a Corvair engine for a Zodiac CH601 HD project using your Manual and info from your Q & A on your Web site.

    I am hoping for about 110hp using the OT-10 cam, forged pistions .060 overbore (because .010 not available) and other mods according to your Manual. I would like to know whether a Stromberg NAS-3 with 32mm venturi is large enough to produce 110 hp.

    I have contacted a local machinist to make a safety shaft. He would like to know whether the two grooves are necessary (one is 1" from one end, the other is 2" from other end). Can these grooves be eliminated?

    Would a 2-blade, 68" Warp Drive prop, #N6515 be suitable for my project?

    Bob Duns, Zodiac CH601 HD, Manual #5053, rduns@sasktel.net
    Reply from WW:
    Getting a full 110hp out of a standard displacement Corvair involves winding the motor up to approximately 3200rpm. This will not harm the motor at all. The two considerations you mention are prop diameter and carb venturi. In the interest of more power, I would suggest the larger 1 3/8" Stromberg venturi. The smaller one is effectively limited to 85 or 90hp on a Corvair. To wind the motor to 3200rpm, I believe a 66" two-blade Warp Drive would be a better bet than a 68". Keep in mind that the Warp Drive is solid carbon fiber and can be trimmed to any desired diameter. Thus, a prop ordered as a 68" could easily be trimmed with a hacksaw.

    The two grooves on the safety shaft are to provide a clean end to the threading. This way, the shaft butts squarely on the end of the crank. It also works to reduce the stress rising tendency of the end of a thread. Over the years, we've had absolutely zero problems here, but the groove style in the drawing is standard engineering practice.

    Subj: Corvair for Zenith CH 701?
    Date: 6/26/03

    I have been looking at the Zenith 701 design. While it is aesthetically challenged, it has its advantages. I noticed it has been built with many different engine installations. Do you know if one has been built with a Corvair conversion? What are your thoughts on this application? Thanks in advance,

    Karl F. Counts, Karl@CountsFamily.com
    Reply from WW:
    I recently exchanged e-mail with Sebastien Heinz, in which he reiterated his family's position that the best engines for the 701 are the lightest ones, although their Web site and advertising shows engines that are heavier than the Corvair, like the O-200 and EA-81s with reductions. If the airframe will fly with the weight of these engines, the airplane will certainly fly with a Corvair. Sebastian just feels that it's better off with the lightest motor you can get.

    Subj: Ignition
    Date: 6/25/03

    Using your dual points distributor, one must need to employ an "automatic coil selector," since both sets of points use the same plugs. If one coil shorts (the old shorting tach question) does the coil selector default to that set of points?

    John Sandt, Avid or Kitfox, Calif., josandt@netzero.com
    Reply from WW:
    The coil selector has no moving parts. It functions as two diodes. What is selecting which ignition system you're on is a panel mounted switch providing 12volt power to the positive side of either your A or B coil. Thus, you have to manually switch it to the other side. Although you can run both at the same time, it is not recommended by the manufacturer. On all installations, I recommend this switch be put in a position where you can change it without removing your hand from the stick or the throttle.

    Subj: Corvair in Brazil
    Date: 6/24/03

    Thanx for your response. I saw Mr Tadeu's message at your site and contacted him, congratulating him on finding a Corvair (alive!) here in Brazil, which is almost impossible. Unfortunately he found only one! Time is not really a concern, as I didn't really start my KR2S yet. FYI it's quite possible that I will show-up at Oshkosh this year and them we could talk directly. By the way, I was at Sun 'n Fun and watched your forum. Best Regards,

    Oswaldo, KR2S, Rio de Janeiro, Brazil, oswaldo10@globo.com
    Reply from WW:
    If an engine does not turn up by the time you need one, I certainly can arrange an export if it's required. I have shipped engines to England and Australia. I have great respect for anybody who would build an airplane under what have to be more challenging circumstances than anyone would face within the United States. Most U.S. guys don't stop to realize how lucky we are.

    Thank you for coming to one of my forums at Sun 'N Fun. Although there's always a crowd around, I am very much a people person, and under these circumstances, especially if we haven't had the chance to meet before, I encourage anyone to introduce themselves and spend some time with us. I attend these events from coast to coast specifically to meet people in person. The forum is just a way of starting the discussion. I'm looking forward to meeting you and many other friends, new and old, at Oshkosh this year.

    Subj: Avid Mark IV and Corvair
    Date: 6/23/03

    I have an Avid Mark IV..is the Corvair well suited for this aircraft? I now have a Rotax 582 and am considering a VW... Corvair...or a Subaru... Thanks,

    Mike Allman, Avid Mark IV, Knoxville, Tenn., MCALLMAN@aol.com
    Reply from WW:
    We have a couple guys working on Corvair installations on their own Avids. On the Mark IV, it's important to have the heavy duty model for any 4-stroke installation. The Corvair motor falls between the VW and the Subaru for installed weight. A typical Corvair is approximately 35lbs. heavier installed than a Type I VW. With a conversion to VW cylinders, the weight difference on the Corvair would shrink to 26-28 lbs. And of course, the Corvair engine would have 900cc+ (about 55cid) more displacement. The Subaru EA-81, with its smallish 1800cc displacement, has to be worked very hard through a belt reduction to be in the same power league as the standard Corvair engine. In recent years, builders have removed several EA-81 installations and replaced them in the same aircraft with Corvair power plants. In all instances, the Corvair was substantially lighter. Although the EA-81's base motor may be lighter than the Corvair, its proponents frequently tout the engine's weight without the hoses, water, radiator, thermostats, etc., that are required to go flying. I don't know why this practice is tolerated, but it's silly. In a typical case, a standard Corvair motor with iron cylinders in a direct drive format will be 35-40 lbs. lighter than an EA-81 with its required PSRU ready to fly.

    Subj: Vari-Eze
    Date: 6/22/03

    Can you give me a source for information and your opinion about using the Corvair engine to power a Vari-Eze? Thank you.

    Del Ralston, N770DY, drals1234@adelphia.net
    Reply from WW:
    We have several people working on VariEz installations of Corvair motors, but I'm not aware of anyone currently flying this combination. I did a design study and built a motor mount for my friend Arnold Holmes' VariEz. He has since sold the project to a group of builders in a Minnesota EAA chapter. Arnold and his father are planning on moving to a grass strip, which would not be favorable for a VariEz. I intend to stay in touch with the new owners and will keep you posted on the installation.

    Subj: Corvair engines (of course!)
    Date: 6/21/03

    I am in receipt of your wonderful Manual, I've read it through at least three times and I want to thank you for its simplicity and real educational value. Thank you.

    I've started to look for an engine and I've found that people who have the engines we want DO NOT ADVERTISE THEM! They'll advertise a turbo or a 140 HP, but not a 110 HP. If you contact someone who is selling a 140 HP and ask, he'll probably have just what we need, but he didn't think it had much value, so he didn't include it in the ad. There's even one advertisment on e-bay right now that is for two 140 HP engines; if you buy the two 140s, he'll throw in a 110 HP engine for free! Ironic, isn't it! The real stickler in all this is the cost of shipping an engine. I can't seem to find one local enough to just drive there and pick it up. Does Clark's sell used engines? I'm in Massachusetts.
    You should have my order for the Quarterly Newsletter by now. I am looking forward to having a rewarding time building my Corvair engine and deciding on the correct aircraft to build to complement it. Thanks again,
    Gerald N. Scampoli, Mass., GScampoli@HomeMarketFoods.com
    Reply from WW:
    That is a very keen observation you've made on 110s. A 180 turbo or 140hp Corvair motor is worth five to 10 times what a 110 or 95 is. So, your observation may be even more common than you suspect. Keep running down leads in your own area. Massachusetts has a reputation for being rich with Corvairs. Clark's does sell whole engines when they have them, and they have a huge selection of used parts also.

    Subj: Corvair Cranks
    Date: 6/20/03

    I'm wondering what your process is for adressing crankshafts. Do you automatically do the 10/10, do you expect it to be done before you get it, or do you handle it on a case by case basis subject to inspection? Are you doing the regrinds, or sending that out?

    Another question is: Is there an advantage to regrinding an in-spec crank just to clean it up, or is there a downside to the regrind which makes avoiding it desirable?
    What exactly are the options here? I suppose I could have it reground locally, and then send it your way for safety shaft modifications, or perhaps the other way around would work too.
    My thought is, if you are outsourcing the machine-shop work, there is probably not a lot of use in sending you the raw crank, causing you to have to do the legwork to send it somewhere else. Conversely, I want your hands involved in the safety shaft because I want somebody who knows how it's supposed to look when it's done. Thoughts?
    Clay "Hoppy" Hopperdietzel, Vision, Tomball, Texas, hoppy@houston.rr.com
    Reply from WW:
    The grinding and threading are handled for me by two craftsmen who have done virtually all of them since 1997. (I never publicly identify who these guys are because they are small businessmen with families and I would never jeapordize their situations in the litigation prone world of aviation. In all of my years in business, I have never been involved in a lawsuit, but I would not have these fine craftsmen be made nervous by unnecessary publicity.) These guys are very, very good, but the jobs they tackle on the Corvair stuff would not challenge any competent guy in your area. To address the safety shaft issue, I suggest you purchase one from me ($66 for U.S. orders, $81 for international orders, by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802 or by credit card at the FlyCorvair.com Online Catalog) so the machinist can have it in hand when he threads the crank.

    If your crank is within factory limits, then it is perfectly acceptable to fly it. Most machine shop guys agree that engines operated continuously at high output benefit from looser tolerances on the bearings.

    Subj: Possible engine for Fybaby Project?
    Date: 6/19/03

    I'm looking into getting a partially-done Flybaby project. I'm a newbie, and have never done any home-built projects before. The plane comes with a Continental O-290G, which I'm told is too heavy for the plane. A friend gave me your Web site, and I'm very intrigued. Would a Corvair engine be as light or lighter than a Continental O-200/ 85 Hp? The cheaper aspect of the engine certainly is appealing - especially to my limited pocketbook. The 6 cylinders seemingly would make it a smooth-running engine. Has anyone else used it for a Flybaby before? Any info or advice would be greatly appreciated. Thank you,

    Jeff Patnaude, Snellville, Georgia, EAA 690, patnaude@comcast.net
    Reply from WW:
    Good to hear from you. As you probably know, the Flybaby was designed in the early 1960s by Peter Bowers, one of the aviation greats of all time. It is a sad note that Peter Bowers passed last month. Aviation as we know it is far richer because of Peter Bowers' writing and photography. His aviation photography collection and his knowledge of light aircraft are unmatched. We can only hope that his collected works will be made available to the public via a university or EAA headquarters. I am sure we will see excellent coverage on the life and times of Mr. Bowers in a coming issue of Sport Aviation.
    As for the Flybaby, it's a great design and was built in large numbers. You are quite correct that an O-290G is the wrong motor for it. It was intended to be powered by one of the small Continentals, 65-100hp. Just a note: An O-200 is 200cid and 100hp at 2750rpm; a C-85 is 85hp, 188cid, and rated at 2575rpm. The Corvair motor in its standard configuration would make an excellent motor for the Flybaby. The engine's low cost and plans built nature complement the Flybaby philosophy perfectly. Electric start would make a nice touch to make the plane easy to operate. In this configuration, it will weigh about the same as an O-200, but be far smoother. And of course, it will not require raiding your Swiss bank account.
    Additional good news is that your O-290G, if it was converted correctly to an aircraft engine, is worth far more than you will spend to completely overhaul and convert a Corvair motor to flight ready status. Even a worn out O-290 will bring far more money than the wonderfully inexpensive Corvair will cost you. Welcome to the wonderful world of Corvair economics - initially hard to believe, but true.

    Subj: Starter mount
    Date: 6/18/03

    I have a question about the new front starter mount mentioned in the Spring 2003 Corvair Flyer newsletter. I noticed in the picture that the left hand mount appears to have a tab welded to it , and the "link" is attached (bolted) to it. In the drawings on Page 9, you show a 3/8s bolt welded to the 3/4 square tubing. I am assuming that the 3/8 bolt goes into the starter mounting hole. My question is which of these two methods is the most recent? They both appear to be a much better idea than the welded 1/4 mount with the hole, from the Conversion M anual. Also, I would think that the mount with the 3/8 bolt would drop the starter an additional inch or so - is this right? Regards,

    Doug Cowlthorp, CH601XL, Winnipeg Mb., Canada, thorp@escape.ca
    Reply from WW:
    The first generation of front starters are characterized by an aluminum angle bracket and the method shown in my Conversion Manual shows how to fabricate your own aluminum bracket. While this worked and flew many hours, with examples of it flying as far away as Australia, this is now being superseded by the mount characterized with the welded square tubing and studs as you mentioned. Just so we have terminology so everyone can be on the same page, we'll refer from now on to the early style as the original front starter, and the new model will be referred to as the low profile front starter.

    You have very sharp eyes, and are a good observer. The pictures above, below and on the back of The Corvair Flyer are of the prototype of the low profile starter. The drawing in The Flyer is how we're actually shipping the parts. It does have a 3/8" stud in place of the tab and bolt, and is a detail improvement.

    The low profile starter is a height reduction of about 1". More importantly, it's easier to fabricate and is adjustable in height, and therefore more forgiving of each individual assembly. It's slightly lighter also. I've studied the whole system in great detail, and I'm now very satisfied with it. Accordingly, I've had batches of the parts made up so I can offer kits. It's going to be the only starter system I'm putting on all the motors I build from now on.

    Subj: Kolb MKIII
    Date: 6/17/03

    I have been flying a Kolb MKIII for several years, and have owned several Corvairs since I was 20 years old (a long time ago). My airstrip is only 750' long, and the MKIII takes off MUCH quicker with a 68" prop instead of a 64" prop. I assume that the only way to swing that big a prop with a Corvair engine is by adding a reduction drive, is this feasible? Thank you.

    Richard Pike, rwpike@charter.net
    Reply from WW:
    I recently have thrust tested propellers as large as 72" with succesful results on direct drive Corvair engines. Although I personally prefer slightly smaller props, even on the slowest of airframes, I went out of my way to accurately thrust test a Warp Drive prop of this diameter in order to provide factual data for my customers on this. (This thrust test is included on my latest video, Corvair Engine Assembly Part I, available for $29 by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card at the FlyCorvair.com Online Catalog .) There is a bit of a misconception among homebuilders about the upper rpm limits of certain prop diameters. Keep in mind there are certified props for 2,700rpm Lycomings as large as 86" in diameter, which of course are run direct drive on aircraft with forward velocities far in excess of very light aircraft, like your Kolb. In short, each airframe/propeller/engine combination needs to be optimized as a unit, but the Corvair can certainly turn propellers direct drive as large as most homebuilt airframes can physically accommodate.

    Above is a photograph taken during a thrust test of the 72" Warp Drive propeller. The top gauge shows a very accurate 2708rpm static. It has a pitch setting of 9 degrees. This would be appropriate for a Pietenpol, J-3 or Stork. The RPM is measured with a digital, optical prop tach. The bottom gauge, $20, is reading in PSI. This is reading the hydraulic pressure in a hydraulic cylinder in tension, restraining the test stand from rolling forward. It is in direct line with the crankshaft. The area of the hydraulic cylinder is 1.52 square inches. Thus, the actual thrust is 380 pounds. Keep in mind that we are running stock, cast iron exhaust manifolds, and a full exhaust system with an automotive muffler for sound suppression (my hangar is in a residential airpark). Additionally, the engine has no cowl, but is using a 7"x24" air scoop 6" behind the prop. The test stand has a mock firewall, which is a blunt 30"x24" rectangle 14" behind the engine. From testing of cowled airplanes with flight exhaust systems, I can assure you that they thrust test much higher. Nonetheless, 380 pounds is a very respectable number, and would do a great job flying a J-3 sized airplane. Compare this with a C-85 powered fully cowled Cessna 140 with a 72" metal propeller pulling 385 pounds measured by myself with the exact same equipment. I've frequently heard numbers thrown about in the 500-600 pound range claimed on behalf of engines ranging from 65 to 125hp. When investigated, most of these claims don't stand up, so I would caution people not to draw conclusions when comparing numbers. Many people who have attended Corvair College have seen my test equipment and verified its accuracy.

    Subj: Maximum propeller diameter
    Date: 6/16/03

    Thanks for your reply, William. I appreciate your thoughts on this project (Piet for Big Boys) and I do give more credence to you guys who have actually built and flown a Piet. I'm not planning to stray too far from the general proportions of the original Aircamper but I did stretch the aft fuselage for greater leverage for the increased pitching moment of the 4412 airfoil as well as increasing the vertical and horizontal tail surface areas (using a scaled up Sky Scout tail feathers profile). Of the few Piets I've flown in, I've always thought an increase in tail volume would improve directional and pitch stability even on the stock Piet. Just to clarify.... With one of your 'stock' Corvair conversions on a Big Piet your suggestion for a wooden propeller diameter is 68 inches? Any hint as to pitch recommendation? I plan on making the prop myself (education, $ savings, aesthetics, fun and satisfaction) but I always listen carefully to someone with your firsthand experience. Thanks again for your input.

    Arlen Anderson, Pietenpol, Papabear108@aol.com
    Reply from WW:
    Prop pitch measurement varies from manufacturer to manufacturer. One man's 32" prop is not the same as another's. If you wish a high cruise of 80mph, at 2,800rpm, the following math would suggest

    80mph = 7040 feet per minute

    7040 x 12 = 84480 inches the plane will travel forward in one minute

    If you divide this amount of inches by 2,800 revolutions in the same minute, it will give you the number of inches forward motion per revolution, in this case, 30.17. This is your inches in pitch. You can work these formulas many different ways, but to absorb a certain amount of hp at a certain rpm, you need a very specific amount of blade area. An engine that's operating at 25" MAP and 2,800rpm and producing 75hp, like a Corvair, could be called Case A. Conversely, a Continental A-75 would require about 2,500rpm and 25" MAP to produce the same horsepower - Case B. But, the difference between the amount of blade area required on Case A and Case B is quite substantial. The Corvair motor would require approximately 25% less blade area to effectively transmit the same hp into thrust. This is why big, geared, slow turning props have to be much larger. If you turn props very slowly, they have to have a lot of blade area to produce thrust, the same way that if you're going to fly an airplane very slowly, it has to have a lot of wing area to produce lift.

    The greatest old wives' tales told in aviation by people who have never directly experimented with the engines they're willing to talk about is that the larger, slower turning prop would somehow be magically more efficient. Having owned, tested and flown all types of props, thrust tested them scientifically, and worked for or been a dealer for a number of major prop manufacturers, I can assure you this is an old wives' tale that isn't true.

    The 68" propeller I was referring to was a Warp Drive two blade with squared tips. A wood prop should be slightly smaller, perhaps in the range of 66". There is a lot to the art and science of wooden propeller making. I've never seen anybody on their first shot produce a wooden prop that would work anywhere near as well as a Warp Drive. Very experienced wood prop makers can slightly exceed the performance of Warp Drive with a custom made wood prop. I'm not discouraging you from manufacturing your own prop, I'm just telling you that you need to be armed with a lot of good information. Most of the stuff people publish on props is trash. If you want a good starting point, the 1930 edition of Fred Wick's book on props is the bible. And I would not attempt to build one without Hovey's book on practical prop making circa 1985.

    Subj: forged piston source?
    Date: 6/15/03

    Are forged pistons available currently, and if so, what is the source? Also, Corvair Underground is really pushing the Ken Black hypereutectic pistons as being as detonation-resistant as forged. Are these the same hypereutectic pistons that you've already written about in the manual? Thanks much,

    Jeff Boatright, Manual #5245, jboatri@emory.edu
    Reply from WW:
    Under no circumstances are hypereutectic pistons as detonation resistant as forged are. It is irresponsible for people to suggest that they are. The Blacks are made by United Machine and Technology, and the manufacturers do not claim them to be anywhere near as detonation resistant. The whole story on pistons was in the last issue of The Corvair Flyer. The engines I'm currently building are using the 88mm VW forged pistons from SC Performance.

    Subj: Corvair in a Zodiac CH 601HDS?
    Date: 6/14/03

    Any thoughts or info about a Corvair in a Zodiac CH 601HDS. I'm interested in building something with a Corvair and have never built before.

    Mark King, kinglabwest@earthlink.net
    Reply from WW:
    The Corvair/601 is a very popular combination. I'm currently working on motor mounts and other installation pieces for this combination. Keep an eye on www.FlyCorvair.com for details. Please note that most guys building today are building the XL model, a serious improvement over the earlier models. You may wish to consider this.

    Subj: Wittman Tailwind
    Date: 6/13/03

    I have a carb from an old C-75 Continental, will it work on the Corvair? Also are there any Tailwinds you know of currently flying a Corvair engine?

    Stan, Tailwind9@msn.com
    Reply from WW:
    There's nobody I know currently flying the Corvair/Tailwind combination, although it has flown in the past. We have several experienced builders working on the combination right now, so before long, we'll have several fresh flyers on this front.

    A lot of my flying time was done on an NAS carburetor, which I believe was the same carb used on the C-75. They have different venturis, but the 1 3/8" venturi has supported well over 100hp when installed on a Corvair motor.

    Subj: Exhaust Stacks
    Date: 6/12/03

    I am interested in a set of your exhaust stacks for a 95hp engine (head numbers 3878569). Do you have any pictures of them? I have to heat the heads to remove the old stubs, how do the new ones fit? Can they be fitted with the valve etc. already in the head? Thanks.

    Peter, vk3eka@yahoo.com
    Reply from WW:
    My exhaust stubs bolt directly onto the stock heads with their steel stacks in place. They are not a replacement for the stock piece, they are the beginning of your exhaust system. We will have more pictures next week on the Online Catalog at www.flycorvair.com. We're revamping this right now. It will have much better explanations, and they'll be much easier to see.

    The stock exhaust stacks can generally be removed from the head without heating the the head. I'll post a picture of the lever mechanism I've used to pull hundreds of stacks from heads. You only need to do this if you have bad stacks. My exhaust stubs will bolt right onto original exhaust stacks.

    Subj: CORVAIR FLYERS
    Date: 6/11/03

    IS THERE A WEB SITE FOR CORVAIR FLYERS?? THANK YOU FOR MESSAGE ABOUT ZENITHAIR 701 & CORVAIR. HAVE MY WINGS & RUDDER DONE.THANKS.

    MAX BUTLER, ZENITHAIR 701, CHEYENNE,WY, MB160016@exchange.DAYTONOH.NCR.com
    Reply from WW:
    If you would like to see a partial collection and information about flying Corvair planes, just check out this new part of our web site: Flying Corvair Planes!. It's a work in progress, and we're trying to add to it all the time. Check it frequently for updates, as the results of our Corvair Questionnaire continue to return from all parts of the country. This is my favorite part of the Web site because it's a pleasure to admire the craftsmanship of these builders and aviators. It should fill the rest of us with motivation to go out and complete our Corvair powered birds, taking our rightful place amongst the group of builders now enjoying the fruits of their labor and the freedom it gives them.

    Subj: Engine to prop
    Date: 6/10/03

    Can the engine main withstand the prop torque? Any possibility of a super charger for added power?

    jchelmecki@aero.net
    Reply from WW:
    I assume you're speaking of the main bearings of the motor, specifically the thrust bearing in the engine. The Corvair motor has a double sided main thrust bearing, which has a perfect track record during the past four decades of powering the aircraft. You can find the complete story further down this page by hitting Ctrl+F and typing in "bearing." In short, the motor needs no external thrust bearing in a direct drive application. I'm currently working on a turbo charger to boost the power of the application. More details as they develop.

    Subj: Metal plane to match Corvair, of course
    Date: 6/9/03

    I have been surfing your site for an hour and am excited to think that the Corvair engine is what I am looking for, inexpensive and reliable.

    I have not settled on a plane, other than I want to make it out of aluminum, as I am a machinist with a shop and am comfortable with metal.

    I will beg your indulgence and ask for your opinion about just what kit plane to make. Fast would be nice, but I am realistic about that. Something matched to the motor makes sense to me.

    I am located just NE of Orlando, and would like to come over for a class about working with the Corvair engine. Thanks in advance,

    Terry Warburton, Geneva, Fla.
    Reply from WW:
    Welcome to the club. There are a number of metal aircraft designs that match the Corvair very well. If you're interested in a single seat design, Kevin Bishop's Ellesay is currently heavily into the prototype stage, and it was specifically designed for Corvair power. Amongst two-seaters, the Zenair 601 is very popular with Corvair builders. Neil Hulin is our point man on the Corvair-601 project. I am developing the installation for his 601XL project, but there are many, many other guys in the field working from my Conversion Manual on the exact same match.

    Feel free to stop by at any time, just call first to make sure we're here. We travel to airshows, fly-ins and EAA Chapter meetings quite a bit, but are always ready to play host to anyone here to learn.

    Subj: Replacing crankcase studs
    Date: 6/8/03

    I have a question regarding the replacement of crankcase studs. I purchased a motor from an individual who pulled it from his car and stated it had a blown head gasket. After teardown I could not find any evidence, although I am not sure what a blown gasket would look like, they look fine to me. However, when I was removing the heads I did notice three of the stud nuts in the area of one of the center cylinders did not seem to have as much torque. About half a turn and they were free. The area around the base of this cylinder was also very dirty/oily as compared to rest of engine. To be on the safe side I thought I would go ahead and helicoil all the studs. My question is, after helicoiling can I reuse my studs? The green shop manual mentions studs are available in .003 and .006 oversize. Clark's catalog says to use .006 if you helicoil. Also, do you torque the studs the same when using helicoils? Thanks.

    Mark Sandidge, Madisonville, Ky.
    Reply from WW:
    Yours is an excellent technical question. The sign of a blown head gasket is some of what you described, plus obvious blow by at the top of the cylinder. I would not assume just because it had a blown head gasket that it was pulling the studs out of the case. Careful inspection is in order. Take a straight edge and compare the height of all the studs. They should be within 1/16" of each other. If none of them unscrewed on disassembly and they're all about the same height, and there's no obvious defects, your blown head gasket may not have damaged the studs.

    Clark's is a good outfit, but they are mistaken on this one issue of studs. As stated in the Conversion Manual, the thread on the stud is NC5-16, not 3/8-16 like a helicoil. Use the split die method outlined in the Conversion Manual (available for $59 in the U.S., or $64 including S&H outside the U.S., by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog) if you are helicoiling and use the stock size studs.

    A stud that screws into place when using helicoils must be locked down using thread locker. My preferred LocTite is 620. A stock stud is like a pipe thread in that it bottoms out at some point. Any helicoiled hole is like a nut and a bolt.

    Subj: Usable heads?
    Date: 6/7/03

    I have just recieved two engines from the US. They are:

    Motor 1 RU with 8049 crank and 3880708 Heads; Motor 2 is an RG with 8049 crank and 3878569 heads.

    The RU is in better condition. Your Manual states that both are unsuitable (page 19), yet page 46/47 says the 3878569 heads are OK. Could I use these heads on either engine? If so, I presume I would only need another set of suitable heads for the second engine.

    By the way, I have now moved from St. Helena back to Australia; much better airplane building environment! Thanks for your time.

    Peter, Australia, vk3eka@yahoo.com
    Reply from WW:
    Both of your blocks came from the factory with something called AIR installed as a system on the engine. AIR is not air conditioning, but rather emissions control equipment. Stripped of their external paraphernalia, the only thing about these engines that would then be unsuitable for flight would be their no quench area combustion chambers. You are correct that acceptable heads could simply be swapped onto these motors. As evidence, this already has been done on the engine you referred to as Motor 1. The 0708 heads did not come on the RU motor from the factory. But, they are excellent heads for a flight conversion. In short, Motor 1 is ready to go. There is some debate about the heads on Motor 2. The 8569 heads are listed as 8.25:1 compression, and I think they probably have a quench area and are suitable for flying. Complete open chamber heads, such as the turbo heads, are the ones that are not suitable for flying. GM literature lists these as 8:1 compression heads. A 3883862 is an example of a 95hp open chamber head. All you have to do to verify that Motor 2 is ready is check for the quench area in the combustion chambers.

    Congratulations on getting two good core engines to the other side of the earth. This goes a long way to prove that anybody who wants Corvair power for their experimental aircraft can readily have it. Certainly everyone in North America can readily find a motor if they want to.

    Subj: Pietenpol Power Curve, Props
    Date: 6/6/03

    My nephew & I are researching the possibility of using a Corvair engine on a Pietenpol. Do you have available the power curve on the engines?? What prop would you recommend?? Thanks.

    Harry Myers, harrymyr@vtc.net
    Reply from WW:
    As you already know, the Corvair is the ideal engine for the Pietenpol. The updated long fuselage drawings available from the Pietenpol family are the most ideal ones to build from for Corvair power. The Corvair engine, built according to my Conversion Manual (available for $59 in the U.S. (and $64 including S&H outside the U.S.), by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog) produces about 80hp at 2,800rpm, 90hp at 2,950 and 100hp at 3,100rpm. I sell 2-blade Warp Drive 68" ground adjustable propellers for Pietenpols, the same prop I flew for years on my own Pietenpol with great satisfaction. Most guys flying wood props use 66" diameter with a pitch in the range of 30-34". Happy building and flying your family project.

    Subj: How Sweet it is!!!
    Date: 6/5/03

    As you are aware, I am running the 32mm Aerocarb on my engine. The engine, prior to yesterday, had 7 hours running time on it. One of the things I had been having trouble with was low idle rpm. I simply could not get the engine to stay running below 1000 rpm. I was beginning to think that the 32mm carb was not right for this engine and I might need a 35mm. So, I decided to study the manual on the carb again and see if there was anything out of the ordinary I was doing. The manual stated the carb comes with three needles for proper tuning to the engine. Number one is leanest, number 3 is mid range and number 5 is richest. So I got to thinking about this, and it seemed to me at low idle I simply could not get enough fuel to the engine to keep it running. I took a look at the two spare needles I had and they were #1 and #3 so I decided to remove the one in the carb to see what number it was and it turned out to be a #2. Well what do you know, I installed the #3 and followed the instructions on tuning the carb, hit the starter, and she fired right up. I allowed her to warm up at 1000rpm then began to slowly lower the rpm and reached 600rpm. I was awestruck. This engine was purring like a kitten at 600rpm with absolutely no vibration. I simply could not believe the performance I was getting now that I installed a needle which gave me a richer mixture at idle. Once again I am on top of the world with excitement about the Corvair engine and I would like to thank both you William and Grace Ellen for all you guys have done to get me to this stage. Also, I hope a visit to my house is in your plan when you visit Broadhead and Oshkosh this summer. I have bragging rights you know and you must see how I have progressed since you were here last summer. How Sweet It Is !!!

    Mark Jones, KR2S N886MJ, Wales, Wisc., flykr2s@wi.rr.com; Visit my KR-2S CorvAIRCRAFT web site at http://mywebpage.netscape.com/n886mj/homepage.html
    Reply from WW:
    Great to hear from you. There comes a point in every man's building where he must break down and suffer the ultimate humiliation of actually reading the directions. I myself am frequently forced into this position. The photos on your Web site do show the great progress. Glad to hear the 32mm Aerocarb is working out for you. Certainly is a quality piece. We're planning on being at both Brodhead and Oshkosh, and we'll certainly stop in on the way, weather permitting. You're not far off our path. Thank you kindly for the invite and the update.

    Subj: Wag-a-bond Power
    Date: 6/4/03

    I am building a Wagaero Wag-a-bond from plans. Fuselage welded and tail feathers. Was thinking of powering with a C-85 or O-200, however looking at the Corvair engine; this might be the way to go. Is the Corvair College still operating? I spend my winters ( Oct. - April ) in Hudson, Fla., and may attend the college next fall or winter if it is available.

    Carl Rivait, Wag-a-bond, Hudson, Fla., rivaitca@earthlink.net
    Reply from WW:
    Here's how good a combination I think the Corvair and Wagabond is: I'm building one myself. I have a completely welded fuselage that has been modified from a damaged Colt. The Wag-Aero plans set fuselage is more closely related to a Colt than a Vagabond. I work on it a couple hours every day with the intention of getting it flying by the end of summer. We'll post pictures of it on FlyCorvair.com shortly.

    Corvair College includes many classes throughout the year, but the big one is in the spring during Sun 'N Fun. You're always welcome to bring your stuff and come by the hangar.

    Subj: Starter Kit Prices
    Date: 6/3/03

    I noticed a reference in passing in your web Q&A that you now have starter ring gears and are looking at stocking complete starter kits. Hey, sign me up. Anything I can get from you I'll buy. The payoff for me is that I don't need to stop building the aircraft in order to run around town sourcing all these bits and pieces. Let me know the extra cost and I'll get a cheque in the mail.

    Neil Hulin, Zenith 601HD, Cincinatti, Ohio, nhulin@hotmail.com
    Reply from WW:
    We have a good supply of the starter kits in stock now because we did all the running around and lots of it for you, and the rest of the gang. Here's the breakdown on the prices, which include U.S. shipping:
  • Bracket set, $79
  • New lightweight ring gear with all machine work done, $89
  • Puck, $189
  • Alternator pulley with all machine work done, $59
  • Replacement Subaru starter gear, $20

    These introductory prices include U.S. shipping until Oshkosh.

  • Subj: Is this a good candiate? Short time window - please answer soon
    Date: 6/2/03

    I recently came across this item for sale: "Corvair 102 H.P. Engine with 94,000 original miles that was removed from my now turbocharged 1962 convertible just 3 months ago. I decided that since I wanted a bit more umph! a turbo would do the trick but had to replace the entire engine. You cannot just turbo charge a standard engine without rebuilding it to turbo specs. The engine is 99+% complete and only missing the mount for the oil filter-readily available. Everything else is there and functions fine. The only glitch is that there is some blowby but no smoke from the tail pipe. The carbs were just recently rebuilt and the engine starts with very little effort. Once started, it has never stalled unless it was my sloppy clutching." The case is stamped T0615YN, for whatever that's worth. Is this a good candidate for conversion? It looks like a heckuva deal. The shipping cost from the Gulf coast to Minnesota may be more than the cost of the engine itself. There's a very short window of opportunity, so I'd really appreciate a quick answer. Regards,

    Corrie Bergeron, Minnesota, corrie@itasca.net
    Reply from WW:
    A 102 is an early model motor, and is only 145cid. It is not a good candidate for a flight engine. The 1964-69 motors are all 164cid and have a few internal differences that make them better motors. I would pass up a deal on any early motor. It's not worth your time to pursue them. There are plenty of 164cid motors to go around. My Corvair Conversion Manual, available for $59 in the U.S. (and $64 including S&H outside the U.S.) by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog, contains all the numbers, codes, etc. so you can get the right engine for your project.

    Subj: Heads
    Date: 6/1/03

    Can I use a 3813513 head on one side and a 3856759 head on the other side? Thanks.

    Jim Daron, Pietenpol, Manual # 5498, Malabar, Fla., cjdaron@cfl.rr.com
    Reply from WW:
    The 513 head is from an early model 80hp and cannot be used with the other head, which is a good one for your conversion. The 759 uses the 1965-69 cylinder, so make sure you find another '65-69 head to match it.

    Subj: Case and Crank
    Date: 5/31/03

    I've torn my engine down to parts, excepting three really ugly case studs which I hope to get done this weekend at a borrowed drill press. Unfortunately, my outside studs were bad enough on the tops to forget any possibility of reusing them, so I decided I'd rather change them all and know what I have.

    I'll probably be looking to send my crank your way after verifying some measurements once I get the service manual. I saw on somebody's Web site that you have a shipping box designed for the task, so what is the usual protocol for doing this? Thanks,
    Clay "Hoppy" Hopperdietzel, Zenith 601HDS, Tomball, Texas, hoppy@houston.rr.com
    Reply from WW:
    Got your phone message. Almost all cranks will clean up with a 10-10 regrind. In land based applications, cranks are commonly reground much more than this in high performance apps. But I only recommend things I've personally flown, and therefore, 10-10.

    I used to ship the cranks in specially made wooden cases. But UPS continuously damaged the cases in a way that they appeared to have been dropped consistently from 3 or 4 feet. Today we ship cranks wrapped in plastic, rolled in a large beach towel, wrapped in bubble wrap, in a cardboard box, by USPS. Seems to work better. If you're building a 3100cc motor, keep in mind that you cannot helicoil any of the stud holes in the case. Be cautious when removing and replacing studs in a potential 3100cc engine for this reason.

    Subj: Bushmaster
    Date: 5/30/03

    I am writing you to settle my dispute with myself over the Corvair. I fly a Bushmaster and really want to do the 4-stroke conversion. Lots of people that I know have installed the Subaru in them and they work great. The Subaru weighs about the same installed wet, but is very expensive to build with a reduction. My question is: If I install the Corvair with direct drive, what can I expect for performance? Will this plane be good on floats? I have been following your stuff for a while, but have not seen a plane similiar to mine yet that has this conversion. My dad is Murray Green. He is very close to having his Stork completed with the Corvair, but I can't wait that long to see how his reacts. Plus his is very high lift. I thank you for any information you can give me to get me on my way.

    Mike, shannon.l@vcm.ca
    Reply from WW:
    We've recently done a lot of very accurate thrust testing on the Corvair, turning a 72" Warp Drive prop. This was done to satisfy the curiosity many people have about the direct drive turning a much larger prop. The engine produced nearly 400lbs. of static thrust for a pitch setting that would be appropriate for an 85mph cruise. This was running the engine with no cowling, a blunt air scoop, and a flat 30x24" firewall behind the motor. The engine also was run with complete cast iron exhaust system and a large muffler for noise abatement reasons. It static'd the Warp Drive prop at 2700. Even at this rpm, the thin Warp Drive blade sections were not excessively noisey. In short, I think the engine would be very appropriate for your aircraft.

    Subj: Pulley p/n
    Date: 5/29/03

    To those using the front mount starter & alt setup per Mr. Wynne's plans, the p/n for the GM pulley has been changed from 3927116-AV to 14087008. You can find new pulleys on the web for $6 + $7 S&H. I purchased mine for $10 from the local GM dealer. Just an FYI. The puck is complete onto the prop adapter.

    Al Manley, Longmont, Colo., amanley@attglobal.net
    Reply from WW:
    Nice piece of homework. Seriously, you win the award for best customer supplied information this month. And the award is: a free one-year subscription to The Corvair Flyer newsletter. We're working in the hangar right now, and decided to institute this new award based on the fact I was having a very difficult time tracking down the new pulley number myself. This is a very good example of how everyone has something to contribute, and why we refer to the Corvair as a movement of friends, as opposed to merely our business.

    Subj: Kit Plane dude
    Date: 5/28/03

    I saw your story in the latest Kit Plane mag.

    Brent Brown, Autogyro, Fayetteville, N.C., brownb@soc.mil
    Reply from WW:
    Thank you.

    Subj: Oshkosh
    Date: 5/27/03

    Will you be at Oshkosh this year? If you are, and I ordered some stuff from you, would it be possible to pick it up at Oshkosh? Items would be Conversion Manual, Aluminum CNC top cover and possibly a crankshaft. All will be paid for before Oshkosh.

    I have just got my engine, a 110hp with all the right numbers. It's going into a GN1. Thanks,

    Ken Rickards, GN1, Markham, Ontario, krickards@CVCI.com
    Reply from WW:
    If we were driving to Oshkosh, I would gladly accommodate your request. However, this year, the plan is to fly by Taylorcraft. It's a 1946 BC12D which has a gross weight of only 1,200lbs. We'll be cutting it close enough with a week's worth of camping gear and the normal products I bring to sell at airshows (Manuals, Videos, Top Covers, Hybrid Studs, Safety Shafts, Oil Pans, etc.). If you have a U.S. address you'd like us to ship to in Oshkosh, perhaps we could save you the across the border fees.

    A quick reminder on crankshafts: I do them only on an exchange basis. You get your exact crankshaft back. I did about 100 cranks last year, and got only about half the cores back. This year, I'm making a special effort to ensure everyone gets their exact crank back instead of the exchange and core program I ran last year.

    You can check the EAA's Web site, AirVenture Forums, for the latest schedule. So far, I am scheduled to speak on Converting Corvair Engines 7-8:15p.m. Wednesday, July 30, in the Aircraft Shopper Online Pavilion 5. Check the AirVenture Forums site later for more dates.

    Subj: Hybrid torque
    Date: 5/26/03

    How much torque should I use on the studs going into the crankshaft???

    Larry Baxter, Manual #5124, Adelanto, Calif., ssshvac@msn.com
    Reply from WW:
    The studs should be double-nutted and torqued into the crankshaft at 22-24 foot pounds of torque, lubricated only by LocTite. Remember to clean off all excessive LocTite after they're torqued in place. The LocTite I recommend is 620. It's expensive, but it's more heat resistant than the regular red LocTite. Please note that we haven't had any problems with the red LocTite, but are still switching to 620 now.

    Subj: Fuel octane
    Date: 5/25/03

    Mark Langford's Web site said he'd burn lower octane fuel in the 3,100cc motor. Is this possible?

    Gordon Alexander, Shakopee, Minn.
    Reply from WW:
    Yes, this is possible. The first person to fly the 3,100cc motor, our friend Steve Makish in South Florida, tested all types of fuel and his compression ratio lowered in a method similar to Mark's. I'm pretty sure that when we broke Mark's motor in at Corvair College #3, we used 100 percent av gas. Although Mark's Web site may not reflect this, I had a phone conversation with him a few months ago in which he explained that after a long discussion with a fuel expert, he's pretty much sold on operating his airplane on 100 percent av gas for many operational reasons beyond mechanical compression ratio. Many people know I'm a fan of 100 low lead, and the technical discussion surrounding this is in the latest copy of the Conversion Manual, available for $59 in the U.S. ($64 including S&H outside the U.S.), by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog.

    Subj: Cozy or LongEZ
    Date: 5/24/03

    Would the Corvair be a good choice for the Cozy Classic or the LongEZ.

    Yosef, y_kristos@yahoo.com
    Reply from WW:
    I believe that the Corvair is a poor choice in either of these aircraft. The only combination I would consider would be a 190cid engine in a LongEZ that was built to Burt Rutan's concept of a very light day VFR airplane. Although these aircraft are thought of as being efficient, they almost exclusively use engines far more powerful than the Corvair. Many pusher canard aircraft have extremely high stall speeds for a single engine plane (they cannot utilize flaps). This high landing speed, combined with the engine's mass behind the passenger compartment, works against your safety in an engine out situation. The logical argument here might be for utilizing only the absolutely most reliable engines operated at their least percent of power output in these aircraft. To me, that would be a large, brand new Lycoming.

    Subj: Camshaft bore?
    Date: 5/23/03

    We just finished tearing down and cleaning two 110 engines. These two engines and one other have pitting in the camshaft bore. How much pitting is allowed if at all? Do you recommend crocus cloth for light pits and buildup and rebore for deeper pits? I would appreciate your input. Best regards,

    Paul Mallard, Miami, Fla., papaquack@aol.com
    Reply from WW:
    There are a lot of old wives' tales about Corvairs wearing out the camshaft bores. This may be an issue for guys building 8,000rpm race engines which will have cam profiles that will require enormous spring pressure on the valves, but for our application, I have found virtually all Corvair cam bores I have inspected usable.

    Light pitting would not bother me, as the bearing area is very generous. I would be hesitant about any technique that would lead to material removal, such as any real sanding, etc. If you truly have the rare case with a damaged bearing bore, I would just find another case. The value of a case is about $50, and there's no conceivable technique to rework one which would cost less than buying four or five spares. A good indication that this has not proven to be a problem in Corvairs is the fact that there really are no methods of reworking this area in the engine. If Corvairs damaged their cam bearing bores frequently, or if the cases were highly valuable like aircraft engines, there would be techniques such as line boring or oversize cam blanks readily available. With the reliability of a Corvair, there's never been a need to develop these.

    We recently had a visitor to the hangar who was nothing short of amazed that there are no cam bearings in the motor. He expressed some degree of wonder at whether or not this brought into question using the engine in an aircraft application. He was even more stunned to learn that no Lycomings or Continentals have cam bearings either, and they have a pretty good record as airplane engines go.

    Subj: Corvair in an Osprey?
    Date: 5/22/03

    I attended your seminar at Lakeland and bought a Manual, No. 5545, and a video and would like to build a Corvair engine. I have bought an Osprey project in Miami and it needs an O-320 to have enough power. I know in your book you mention that the Corvair is not capable of that much power, only 120hp with the large cylinders. I just wondered if you had any ideas for a few more hp, i.e. Rinker box or maybe turbo, stroker, maybe even a direct drives oldsS. I have successfully converted a Mazda which is flying in a Grumman every day, but I don't want to do that again as it was a major pain in the ass and I don't like that gearbox. Kindest regards,

    Bill Fisher, wfisher5@bellsouth.net
    Reply from WW:
    I don't believe the Corvair motor in a simple reliable form can be used to power an Osprey II. An Opsrey is a high performance amphibian with very high wing loading, especially for an amphibian. Most people conclude that an O-320 is the minimum engine. Corvairs have been flown in their large displacement form, with gearboxes and turboed. But I feel that if you combine all of these elements in a single motor, it would start to get as expensive as an O-320, yet would not posess the simplicity and reliability of a run-of-the-mill O-320. It's very hard to get a 164cid engine to do the work of a 320cid engine. And it certainly cannot be done inexpensively and reliably. All of the issues you mentioned with the difficulty converting your previous project, with liquid cooling, gearboxes, etc., are the reason why I focus all of my work on a simple, direct drive, air-cooled engine.

    Subj: Your Corvair engine for sale
    Date: 5/21/03

    I was lucky coming across your adv on Net concerning your Corvair engine of which I've been searching for, with the price of $2,700. Could you please send the pics and tell the condition of the engine so I can make an arrangement for the payment asap.Thanks.

    jcbrazaville@yahoo.com
    Reply from WW:
    I am not sure what Web site still lists this, but the engine was sold several years ago to John Martindale in Australia, who is now flying it in a KR2. The good news is that you can build one yourself for less than $2,700. You start with a Conversion Manual, which will guide you through finding a core motor (not a difficult task) all the way through its conversion and installation. I highly recommend against buying engines offered for sale which are already converted. Very few of these crop up, and in almost all cases, they are converted by people with very low levels of craftsmanship who would be afraid to fly it themselves but would unconscionably offer it for sale so someone else could fly it. The best approach is to build your own motor for yourself. It's what all the succesful builders are doing. Start with the Conversion Manual, available for $59 in the U.S. ($64 including S&H outside the U.S.), by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog, which also lists all the products you would need for the conversion.

    Subj: 95 HP or more?
    Date: 5/20/03

    William, Before I purchase your Conversion Manual I want to know if I'm going in the correct direction. Just purchased a $100.00 1968/69 95HP (no smog) engine.

    1. Will the HP vs weight be ok for my KR2S?

    2. If needed can I increase HP with new jugs and still use the heads.

    I have experience rebuilding several auto engines including many VW engines. If the 95 HP will work I will be ordering your Conversion Manual.

    Steven Phillabaum, KR2S, Auburn, Alabama, skphil@charter.net
    Reply from WW:
    Your late model 95 no-smog engine is the perfect candidate for a KR2/KR2S conversion. We have four KR2s flying now on Corvair power. I think the 2S will be an even more impressive aircraft. All the options of different jugs are available with your motor, but even a basic rebuild and conversion will provide outstanding performance. Additionally, the KR2 is one of the most popular Corvair conversions. I have sold hundreds of Conversion Manuals to people who are now working on this. I've developed and have jigs and tooling for motor mounts, etc., and have spent a significant amount of time to integrate the entire package to make it an easier installation. I went through all of this effort because it is such a good match, and I expect to see a lot more of them take wing this year. The Conversion Manual is available for $59 in the U.S., $74 for international builders, including CANADA, by check or money order in USD payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the FlyCorvair.Com Online Catalog.

    Subj: Sportsman 2+2
    Date: 5/19/03

    I only have read info on the Sportsman 2+2 in Aerocrafter and it lists an O-290 with 135 hp. I have not been able to find weights for this engine but it seems at a glance this could enable a Corvair O-190 fit as there should be a little weight savings. What do you think?

    Scott Schermerhorn, Schermerhorn.Scott@delcoremy.com
    Reply from WW:
    A Sportsman 2+2 is a homebuilt replica of a Piper PA-14. The replicas tend to be heavier than the original, and the original was something less than an exciting performer with a medium-size Lycoming. Today, most Sportsmans are built with 180hp Lycomings.

    An O-290 Lycoming is 290cid and it produces its rated power at 2,700rpm. A direct drive O-190 Corvair could produce the same hp, but it would require much higher rpm, which would necessitate a far smaller propeller. This small propeller would not be a disadvantage on a sleek, small airplane like a KR, but it would not as effectively turn hp into thrust at low speed required for a Sportsman. Thus, the Corvair is not an effective replacement for an O-290, especially in larger, heavier airplanes.

    If you like the Sportsman, you should consider the two-place version: The Wagabond. It is an excellent match for the Corvair, and we have at least two people currently working on them. The Wagabond's original intention was for 100-120hp, which makes it right up the Corvair's alley.

    Subj: Selling the Q-200, 'Vair in a Tailwind?
    Date: 5/18/03

    I have decided to either sell or abandon my Q-200 project for now. I've opted for a Tailwind instead. What do you think about a Corvair in one of these? They have flown on a wide variety of motors, so I think it would be most suitable. I've also been thinking, since they can handle the weight, of turbo-normalizing or even 3-5 psi above SLP. What would you think of this? How much power could you guestimate I'd get with this setup? Finally, which heads should I use? Thank you!!

    Chris McAtee, subcanis@hotmail.com
    Reply from WW:
    The Tailwind is an incredibly good airplane. It is celebrating its 50th anniversary this year. But it is by no means a stagnant design, as major updates were done on the design as recently as the 1980s. I was lucky enough to fly with Steve Wittman in his own personal Tailwind, N37SW. The Tailwind, when built right, is a stunning performer of efficiency. While a Tailwind might be a few mph slower on the same hp, the Tailwind's advantages of a 20mph lower landing speed, the ability to fly off grass, and handling qualities that can be matched by few light planes (which a Q-200 could never hope to match) in my opinion make it a better choice.

    All turbo work without constant speed props is boosted, not turbo normalized. I've done some homework on this, and I feel that the best heads would be the same heads I recommend in the Conversion Manual (available for $59 in the U.S., $74 for international builders, including CANADA, by check or money order in USD payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the FlyCorvair.Com Online Catalog). I would not use the factory turbo heads. With the right turbo, and low boost, you could easily get 120hp. But the real key would be that you could still have 100hp at 10,000 or so.

    By the way, Wittman's airplane that I flew in had the direct drive Olds engine in it. It had a 62" prop that was a cut down prop from an O-200 (this is a bad idea - Don't Even Think About IT). But importantly, the prop turned 3,500 in cruise and produced a lot of efficient thrust. This was the handiwork of Steve Wittman, the acknowledged master of light aircraft efficiency, at his best. When you encounter people who tell you that props should never be spun over 2,500rpm for efficiency, that's their opinion against the experience of men like Steve Wittman. I know which is more valuable.

    Subj: Props
    Date: 5/17/03

    I really hate to ask this question but I know nothing about props. I have a 68" three-blade Warp Drive prop I purchased through Zenith in a FWF package for the Subaru. Can I use this prop on the Corvair with opposite rotation? I e-mailed Warp Drive but did not get a response. I also asked them if I need another prop could I trade in the one I have as it has never been run. I know you are a distributor and was wondering if you could help. Thanks.

    Mark Sandidge, MSandidge@PeabodyEnergy.com
    Reply from WW:
    I know the guys at Warp Drive very well, and they're usually very good about responding. You probably caught them at a busy point. As long as the equipment is brand new, they may be open-minded about a trade in. Doesn't hurt to ask. I was unaware that Zenith had packages for the Subaru. They do have them for the Jabiru, which is a different engine. In either case, right- and left-hand rotation motors require different propellers. On a Warp Drive, the blades are interchangable so you can keep the same hub, and replace only the blades. It's educational to go to the airport, look at a propeller and picture why it cannot be used on a motor of opposite rotation, even if you turned it around backwards. In any case, the right prop makes all the difference on any engine installation, and I'll be glad to work with you to ensure you get it sorted out.

    Subj: Front Starter
    Date: 5/16/03

    I like the simple, improved front mount starter system from the Spring 2003 Corvair Flyer. I purchased the FRA235 and took it to a machine shop to have the center hole enlarged to 3.000". In their opinion, there is not enough space left for drilling more holes. I don't have a puck to verify the placement of the 6 AN3 holes. Could you clarify this for me please?

    Also, I have checked all the major auto parts stores here in Wichita and I'm not having any luck locating the fine tooth gear (Accurate Part No. 4-1001). Could you give me an e-mail address or phone no. on this item please?

    I did e-mail you yesterday about ordering a puck [Received the order last Saturday. You should have received my core distributor by now also. Give me a part number and a price and I'll order a puck. Thanks in advance.]. I think if I had a puck my questions about the ring gear would be answered.

    Thanks again for all your help,

    Barrett Knoll, Pietenpol, Wichita, Kansas, dknoll@cox.net
    Reply from WW:
    You may have missed the Winter 2003 Corvair Flyer which included a drawing of the puck that showed the 6 AN3 holes will fit with plenty of room to spare. My puck part number is FS-1. The price is $189, which includes priority, insured S&H in the U.S. (please add $15 for international S&H, including CANADA). The puck is the only expensive part in my front starter system. It's made for us on a CNC lathe to very exact standards by an aircraft manufacturer.

    I have pulled together all the other parts so I can offer the complete front starter kit or any part of it. The fine-tooth starter gear is in stock, and it costs $22. Its part number is FS-3. Likewise, I have completely machined ring gears, etc. I'm collecting all the drawings and some very nice installation photos into an info pack. I'll post this on the Web site next week. Please check the www.flycorvair.com News from The Corvair Authority page for details.

    Subj: Second Corvair Manual (For a friend this time)
    Date: 5/15/03

    Dear Mr. Wynne, (Sounds so formal.... ahem...)

    Anyway, this is Richard Alps, and you very kindly sent me one of your Manuals. Thanks. It is great! I was going to say supurb, but I can't spell that word. I am currently reading the Manual, digesting it slowly, along with trips to the internet to peruse various CORSA and TCA and KR sites. Loads of info! Whew.

    I may (or may not) have mentioned that I have a friend who is equally interested in aviation, and I have shared the Corvair thing with him. By the way, his name is Ray Green. He lives around the block from me, and has proved to be a trusted and invaluable friend. These kind are rare, as I am sure you know. Anyway, Ray tells me that he is very interested in the Pietenpol Aircamper and/or Sky Scout. I have pics of your Piet, and the story with it. Nuff said about that. Just the same, the Piet is a beautiful little parasol, and you gotta love the design. So, you will find PAY PAL has sent you another $59 to cover Manual #2. He is sitting here as I type this letter to you right now. I just want somehow to clarify that each of us has a legal Manual, and are authorized to associate with the TCA company and all the functions you have put into it.

    In closing, allow me to say thanks for all the work you have provided for the rest of us. Sincerely,

    Richard G. Alps, Littleton, Colo., Richardalps@aol.com
    Reply from WW:
    Good to hear from you. Thank you for the kind words. People saying nice things about us when we're not there is our primary form of advertisement. Thank you very much for your efforts. Please tell your friend that we recently got a lot of new photos of Pietenpol projects that have been flying for years on Corvair power, including a Sky Scout. We'll post these on flycorvair.com shortly.

    Subj: Simplicity
    Date: 5/14/03

    Just this very morning I read your piece in The Experimenter magazine [published by the EAA] and I thought you'd appreciate a piece of wisdom a friend of mine preaches and practices. He's made a living for years installing and servicing marine electronics and electrical systems and says: "If you don't install it it can't break." His own boat is simple and rugged as a rock and so he gets to spend a lot more time on the water than most of the people he works for. I'm a real fan of your philosophy and writing. Please keep up the good work.

    Oscar Lind, Seattle, Wash.
    Reply from WW:
    Thank you for the kind words. The ethic of worshiping simplicity is really the key not only to building airplanes quickly, but also operating them safely. Although I didn't say it in the article, most builders are capable of producing an airplane complicated enough that they could not stay ahead of it in the cockpit. Conversely, I'm much more happy to be a real good stick and rudder pilot who's the master of my simple ship under all circumstances.

    Subj: 140 HP Corsa engine
    Date: 5/13/03

    I have a 140HP Corvair Corsa engine, would this engine work for conversion?

    Stan, lguco063@msn.com
    Reply from WW:
    Although this issue is covered in detail in the Conversion Manual, available for $59 in the U.S. (add $15 for international S&H, including CANADA please) by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the FlyCorvair.Com Online Catalog, I'll give you the quick overview here. The 140hp Corvair motor, distinguished by having two carburetors bolted to each cylinder head, is a high rpm motor which makes its power at an rpm not usable in a direct drive application. Additionally, it is the only Corvair motor with a reputation for poor valve seat reliability. Approximately 5 percent of the Corvairs made from 1965 to 1969 came equipped with this engine.
    Though the 140 is frequently referred to as the Corsa engine, many of these motors went into cars which were equipped with automatic transmissions (all Corsas had manual transmissions). When the 140 is installed with an automatic, it is given a special 4 degree retarded crank gear that needs to be replaced if this crank is to be used for flight applications.
    Everything on a 140 motor, with the exception of the heads, can be used to make a good flight motor. The heads and carburetors are worth several hundred dollars to Corvair car collectors. They would gladly provide you with an excellent set of 95 or 110 heads, which will bolt right on to the rest of the 140 motor. Again, the Conversion Manual has the story in greater detail. This is just an overview.

    Subj: Smog Head?
    Date: 5/12/03

    William, your Manual list heads with the number 3878569 as acceptable to use for conversion. However, Clark's manual lists this head number as a smog head. Please clear up the confusion.

    I was able to find two complete engines with all of the correct designations according to your Manual. The seller included the following engines: 1) a turbo case number T0708, head 3856638, and crank 8409; 2) an engine case number T1004 ZF, head with number 3813516, crank number not 8409. My question, are any parts useable from these engines?
    Paul Mallard, Miami, Fla., papaquack@aol.com
    Reply from WW:
    I do not believe that the 3878569 cylinder head is an open chambered design. The open chambered heads, which have no quench area, are the unacceptable heads. While the particular engine it came from may have been considered a smog motor, I believe this particular head is usable. The final decision point is cylinder heads which have a quench area are airworthy, and open chambered designs are not.
    The ZF case could be a number of different motors from 1961-1964. If it is a 1964, and it is relieved for a long stroke crank, it would be usable. It is probably not a relieved case if it has a non-8409 crank. Your turbo motor is a 1964 150hp. Everything on this motor is usable, except the cylinder heads (see the e-mail below on 5/4/3).

    Subj: Help finding engine
    Date: 5/11/03

    I want to thank you as today I have received the Corvair Manual. Tomorrow I will start the procedure/gathering of information towards importing a Corvair engine into Brazil. If at the end I find that this import is possible/legal, could you help me find a suitable engine? FYI, as I work for the Brazilian flag carrier (VARIG AIRLINES), I travel a lot to the Miami area, so it would be relatively easy for me to forward the engine to Brazil. When the engine happened to be be ready for shipment, I would show up at your hangar, pick-up the crated engine, take it to Miami Airport and dispatch it home myself. At a later date, I would bring you the original crankshaft for the exchange for your modified one, and other necessary parts. Thanx in advance. Best Regards,

    Oswaldo, Rio de Janeiro, Brazil, oswaldo10@globo.com
    Reply from WW:
    Corvair motors seem to be getting popular in Brazil (Please see 5/8/03 e-mail below). If it is not possible to find a motor, given a little bit of time, I can find you an excellent core to begin with. I have sent them as far as England and Australia. When I export a core, I like to take the time to find a near perfect one to avoid international builders having a problem that might be small here, but harder to fix there.
    Over the years, I've probably sold a dozen Conversion Manuals to homebuilders in Brazil. The Ximango motor gliders are imported to the U.S. through our airport here, Spruce Creek, and our friends speak very highly of the time they've spent in your country. We can certainly handle your needs.

    Subj: Spacer for Hand Propping
    Date: 5/10/03

    If the electric starter is left off of the engine (Armstrong starter system to save weight), is a spacer needed under the prop hub? If so, who sells one; you, I hope?

    Joe Hemmer, Orangevale, Calif., kiote@cwnet.com
    Reply from WW:
    The safety shaft and the hybrid studs both have additional threaded length, so prior to installing the hub, they can be trimmed down. Two guys I can readily think of, Pat Panzera and Mark Jones, have chosen to put a small spacer in here, but I would much prefer, and it is much simpler, if rear start and hand prop motors just mount my prop hub flush against the crankshaft.

    Date: 5/9/03

    Friends,

    We were just about caught up with Sun 'N Fun when we had to take several days off due to the passing of the patriarch of Grace Ellen's family on her mother's side. Charles Hayek was 93 when he died. Grace Ellen was his only grandchild. We will be back answering questions Tuesday. We appreciate your patience and understanding.

    Thank you.

    Subj: Greetings from Brazil
    Date: 5/8/03

    Greetings from the Brazilian homebuilders! I'm building a kind-of KR, probably monoplace, and I happened to find a Corvair engine in apparently very good shape, mid life, good compression, runs smoothly, etc. Not a rare finding considering that in the sixties, the majority of cars here were USA-made. Two questions, if you please:

  • 1) Sell me, please, your Conversion Manual. The best way for me to pay you is via credit card, will you take that? And the price for sending abroad.
  • 2) As this engine looks so well preserved, I'm thinking of, in first instance, installing and flying it temporarily with a minimal conversion, i.e., changing oil radiator, carb, top and front plates, manifold, exhaust, etc. (what else?) and installing your prop hub. Then I'd test and fly it until I think it's safe. Is it possible, or should I open the engine in the first place? I know this question will be answered as I read your Manual, but your opinion will enlighten me anyway. Thank you so much.

    Congratulations for the beautiful service pro-builders!

  • Tadeu Passarelli, KR, Brazil, tpassarelli@uol.com.br
    Reply from WW:
    Thank you for the kind words. Yes, I take credit cards. You can order almost all my products via PayPal at the FlyCorvair.Com Online Catalog. Please also click on the $15 button for International S&H.
    I would not recommend flying a motor straight out of the car. The Manual will explain all the reasons why, but the overhaul cost is small compared to the risk of damaging your aircraft and yourself. The motor is very reliable when converted. Much better than when first removed from the car. By the way, one of the most popular songs in America this month is Beautiful, a tribute to the women of Brazil. There's a music video that goes with it, shot on the beaches of Rio. I do not understand where the men in your country have time for airplane building.

    Subj: 701 - RV3 and the Corvair ENGINE
    Date: 5/7/03

    I attended the Corvair Jr. College at San Antonio and am glad to learn that Zenair is going to do the engineering on getting a little more engine weight into the 701 (saves me from getting it done). Gus and I told each other Seabee stories at the Mini College. Tell him I said hi.

    I have seen you mention a couple of times that the RV3 is not a good candidate for the Corvair. I built one of the first RV3s to fly, and while I powered mine with a 160 Lyc., I have 2 friends that chose 0-200s and they both flew VERY nice. Vans early literature states "it would fly fine on even a 65 hp but I don't think that will be a popular choice." Not many new RV3s being built, but the Corvair would make an excellent engine for it.
    Gotta stop buying Corvair stuff. Made a bunch of inquiries when I started looking, and engines, heads, cases and cranks keep turning up. Got enough for half dozen engines I guess.
    The Corvair Club is the way to get an engine. Nearly every chapter has members that have more engines than they need .
    John Bolding, Texas, JNBOLDING1@mail.ev1.net
    Reply from WW:
    Good to hear from you. I told Gus you said hello. We both had a good time on that trip. A lot of serious builders in Texas.
    You have discovered what I tell people all the time is the truth: The engines are truly cheap and plentiful.
    Your experience on RV3s is very close to what other guys have shared with me, that the RV3 can be built as a light, efficient airframe. Three or four guys are working on them along with Corvair conversions, with the understanding that the plane would have to be built light and it will be smooth and efficient, but not in the same league as a 150hp RV3 (it won't be in the same price league either).
    I've noticed over the years that the average empty weights of most examples of the same design appear to be creeping up. If the weight penalty is not bad enough, it's usually a large increase in complexity that goes with it when people turn good sport planes into mediocre IFR platforms. Let's hope the pendulum swings back the other way soon.

    Subj: Exhaust stubs and clamps
    Date: 5/6/03

    I noticed on your Online Catolog you have listed exhaust stubs. Just so I'm clear, they are the stubs that attach to the cylinder heads?? I had a few that were bent and a couple others that I could not remove the gasket material for anything. If they are what I think they are I would like to order a set.

    David Vegh, Chandler, Ariz.
    Reply from WW:
    Good to hear from you. The parts we offer bolt on to the stock steel stack. If you need some stock stacks, I have some good ones I removed from other heads. Let me know how many you need. The cost is $10 each. With a good set of stock steel stubs in place, the pieces we sell give you the beginning of the exhaust system after this.

    Subj: Early Heads
    Date: 5/5/03

    Can early heads be modified to work with a later crank? According to my book, they are 8.3:1 CR. Can they be flycut?

    Mark, matee@trib.com
    Reply from WW:
    It's best not to modify the early heads. When you increase the displacement, given the same chamber volume, the compression ratio will increase and your 8.3 will look a lot more like 10:1.

    Subj: Head question
    Date: 5/4/03

    Here is my "Is my engine ruined" question: I certainly don't know much about the engines, and suspect the guy I snagged it from knew litte more than I, so rather than explain what I thought I bought (other than it was a turbo), these are the numbers:

    It does have the 8409 Crank, but the case and head numbers don't seem to match anything in your book. The heads are 3819904. The case is TII05YR (with the caveat that the 'T's and 'I's may be flakey because it's hard to tell the difference).
    Hoppy, hoppy@houston.rr.com
    Reply from WW:
    The motor you've run across is a 1964 150hp turbo engine. This would have been installed in the high performance Spyder. Everything you've got is usable, with the exception of the cylinder heads. You need to find a set of 1964 heads. The acceptable numbers would be 3856626, 3839887, 3839886, 3819876, 3856632 or 3856631. 1964 was a big production year - more than 250,000 engines were made that year. You should have no trouble finding a pair of the above heads. A car collector will certainly trade you, as the 150 heads are worth at least three times what a set of 110s are worth.

    Subj: New Case Assembly Video
    Date: 5/3/03

    I received the parts last night, and viewed the video today. It was wonderful. When are you coming out with the next one?????????

    I do have one question? In the video, when you mounted the two case halves, you didn't use any form-a-gasket or anything. Is that correct, you don't put anything on either side of the case when mating the case halves? Thanks.
    Fish Fischer, Dragonfly, Warrenton, Ore., fishhole@pacifier.com
    Reply from WW:
    Thank you for the compliment on the video. All of our videos are directed, produced and edited by good friend Merrill Isaacson, aka Sky Manta. In addition to being a video wiz, his Corvair motor was on display and run at Sun 'N Fun this year. Making good videos is a snap when you have pros like Merrill doing the hard work. Merrill is currently editing Engine Assembly Video Part II, and we're shooting Part III next Saturday. This trio will cover the whole engine assembly process. Part I is available for $29 in the U.S. (add $15 for international S&H, including Canada) by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the FlyCorvair.com Online Catalog.
    Nothing goes between the two case halves. Between the oil pan, the end covers and the top cover there's only 1/4" of potential leak area. Experience has shown that oil will not come out of this area. Every time someone tries to put something between the two case halves, it effects the clearance on the bearings and allows the case to move. Assemble it bare, just as I did in the video.

    Subj: Rans S6S Coyote II
    Date: 5/2/03

    We're building a Rans S6S Coyote II kitplane. We come to the point of selecting a suitable engine, and the Corvair looks like a great option. We are good at following step-by-step instructions, but not good at welding and building parts for an engine. So we're looking for a complete firewall forward package, ready to bolt on. Can you supply a Corvair engine and the mount materials to fit it onto our S6S? As weight is important, we'd probably need some (or all) of the light-weight options. Electric starter is the only option we'd like to add weight from, and probably the dual ignition too. Can you quote us a price for that? We already own a 3-blade Warp drive ground adjustable prop, beyond that we're open to all suggestions. Best regards,

    Rob, r.turk@chello.nl
    Reply from WW:

    Subj: Questions, Questions, Questions!!
    Date: 5/1/03

    Bob Tolliver here from Butler, Tenn., Manual number 5203. First let me get you up to date. Yesterday, for the first time since I got my Corvair engine, I had some time to start a tear down. I just got my shop manual and finally had a break from college during Easter so I could do something fun. It was nice to be able to get my hands dirty again! My engine looks fair so far. The car had been in a flood, but the water never got over the top of the engine, no water got inside, just moisture. I pulled the top plate off and the cast iron crank looked fuzzy! It had so much light powdery surface rust on it. It seems to be light with no pitting. I have yet to get the heads off or the crank out. The case had enough oil in it to register on the dipstick. At first glance the oil pump even looks good. I will know more after I clean it all up.

    I am having trouble getting the distributor housing out. I have it loose and it will turn, very stiffly, but won't come out. Is there a trick or something to this?
    I have overhauled many engines and have had a lot of luck by just using a cylinder hone and re-ringing the pistons as long as the cylinder is good and round. I have read that this won't work on a Corvair engine. Why not? I understand if the jug needs bored out to make it round again, but if it just needs slight honing why do you need new pistons? I understand there is a problem with possible detonation blowing a hole in a stock piston, but beyond that, why?
    The Roger Mann, RagWing Stork, RW20 is a side-by-side STOL aircraft about the size of a Super Cub and calls for a rather huge 72" diameter prop. I want the plane to have maximum STOL abilities, top speed is not really that important (the Vne for the airframe is 120mph), so what type of propeller do you suggest? Pitch and Dia and where should I get it from?
    On the same note, I have heard mention of building a left hand rotation Corvair engine. Since I need such a weird prop size, would this be the way to go for me?
    In your book you make mention of using new rod nuts. Taking into consideration the low rpm that this engine will be seeing, and the fact that you say a Corvair engine has never thrown a rod, and as long as the nuts are in good condition, why not reuse them?
    I will probably use an aftermarket oil cooler from Summit because mine does not have enough plates. Any advice on this?
    I may have missed it in your book, but why not use the stock carbs that came with the engine? They could be easily relocated underneath the engine on some sort of plenum box and both could be incorporated like a six pack on the old Dodges. Or for that sake even be moved to behind the motor, if the cowl was big enough.
    I have been trying to find a flex plate from a Nissan Sentra, but my auto dealer needs a year. What years do I need to look at? Will the flex plate off of a Chevy Metro work? (I have one I am parting out.)
    Could you E-mail me an updated parts list? If too much trouble, I can probably find it on your Web site.
    Will you have a new Manual coming out any time soon? If so, it would be helpful if you included an index in the back. Also, since you have such experience rebuilding Corvair engines, why not make a manual complete with all the rebuild information in one so there would be no need to obtain an overhaul manual. I tried to get one from every library I could think of and called all the auto parts houses, even went to the Chevy dealer. I had to break down and buy one form Clark's. $20 some dollars to get 30 some pages of information. You could put together a more informative rebuild manual and increase the price of your conversion Manual. It would be much more convenient for us builders. My bedroom has one and a half bookshelves filled with aircraft books already! Now I have about six on the Corvair including catalogs. Just a thought for you to ponder.
    I know I have a lot of questions here, but I would be ever so grateful for your time and answers
    Bob Tolliver, RW20, Butler, Tennessee, Wolfdragon62@wmconnect.com
    Reply from WW:
    Nice to hear you're getting your hands dirty. Some very nice aircraft conversions have been built from motors that at first glance appear to be horrendously filthy and dirty. Careful inspection and measurement should reveal that most of the parts in your engine will be useful in the rebuild.
    A quick correction: all Corvair cranks are forged steel. They are not cast iron. I have seen many cranks that have an external surface coating of rust clean up very nicely. This is from having a tremendous amount of moisture in the crank case over a long period of time. Don't be too concerned about the appearance. Let the clean up and inspection make the decision.
    Soak the distributor in penetrating oil. You can get better access by taking the oil pump out and spraying it up the drive shaft hole.
    My Conversion Manual covers pistons in detail, but I do not like using stock, cast pistons in a flight motor, especially 35-year-old ones. A number of Corvair engines which have had cheap rebuilds for cars fail the top ring groove of the piston because honing does not adequately remove the wear ridge in the cylinder.
    The only prop you should consider for this airframe is a two-blade, ground adjustable Warp Drive. Contrary to popular old wives' tales, a 72" diameter Warp Drive can be used at rpm up to 3,000. This is a perfect match for the direct drive Corvair. I've tested this personally at my own shop, and we had one of these props on display and running during Corvair College #4 at Sun 'N Fun 2003 this year. I sell these props for $580 plus S&H. They have an excellent track record. All Corvair motors are left hand rotation. The option is to build a right-hand rotation Corvair motor, but I don't recommend it. Virtually all the Corvairs flying have been standard Corvair rotation (left-hand rotation).
    The Manual covers this also, but always use new rod bolts. They're cheap insurance. You never know who overtorqued them before you. Although broken rod bolts are unknown in Corvairs, why try and find out what you can get away with, as opposed to doing what we know is better.
    The easiest thing to do on the cooler is spend $25 with Clark's Corvairs and buy a 12-plate cooler. Most aftermarket coolers are designed to fit in front of car radiators and are the wrong shape for aircraft cowlings.
    Yes, I mentioned in the Manual that Corvair carbs have been flown, but I also specify a number of reasons I recommend updraft aircraft carburetors.
    The ring gear from the 1987 Nissan Sentra 120cid motor is the one I've previously used. I've recently shifted to the Ford Taurus ring gear, and the complete update is covered in my newsletter, The Corvair Flyer. This is available, as well as your requested list of all parts and now videos, at the flycorvair.com Online Catalog.
    As for your comments on manuals, let me say this. The GM overhaul manual is an incredibly good book for $20. It is copyrighted information, and is not available for inclusion in my Conversion Manual. The amount of time you spent searching libraries was worth far more than the $20 something you spent. I have worked very hard to hold the cost of my Manual down, and people respect this. It takes an efficient operation like the one that I run to sell hundreds of Manuals a year for the modest price I ask and still maintain the customer service standards which allow me to personally answer letters, no matter how long they are, from individual Manual owners. Do not fret over having more books on your shelves. I own a houseful of technical manuals, and I have come to notice that the people who build the most airworthy airplanes tend to have thick bookshelves. People reluctant to gather and use information tend to have dormant projects with dozens of glaring mistakes that could have been avoided had they indulged themselves with a few of the commonly available books. Isn't this the philosophy that led you to college in the first place?

    Subj: Eagerly awaiting new Conversion Manual
    Date: 4/30/03

    Nice work with spreading your knowledge on the Corvair conversions. I'm pretty handy, but I'm not a motor head by any means. I'm trying to learn all I can to use the Corvair engine. Thanks for including the copy of the newsletter. If I can learn from it, I'll order it. I really want to learn about what carb to use, and the differences between them (Corvair carbs, updraft, downdraft, sidedraft, throat sizes, gas tank location for head pressure....all that stuff). I need to learn when to use a starter and when not to, and what's up with the blower on top; some people use it, others don't....
    I hope I can learn these things with the help of people like you and your newsletter. I am also interested in attending your Corvair College one of these years. I'd like to know if I need to bring all the new parts with me, or can we buy them down there.....
    p.s. I wonder how long my engine mount should be. Do I need to build and cover the whole plane before I know how long to make it?
    Thanks again.
    John Egan, Litchfield, Ct., jegan@kcc.com
    Reply from WW:
    The Manual you ordered will answer all of your questions asked here, but let me take the opportunity to answer them here quickly so everyone else can learn as well.
    You mention not being a motorhead. Don't worry about this. The vast majority of Manual owners have never rebuilt an engine before. This is not a handicap. In fact, it means you're much more likely to follow the plans and do careful work.
    The Manual, available in the U.S. for $59USD by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15USD for international S&H, including CANADA), covers all types of carburetors and fuel systems and the airframes to which they are applicable. In short, the Corvair will run on a multitude of carburetors. Most of the hours with the engine have been logged on a Stromberg NAS3 (from the C-85 Continental). Today, the two most popular carb choices are the MA3SPA (O-200) and the Monnett AeroCarb.
    As for electric start, I cover all the issues on front and rear starters in the Manual. I have built and flown both in several versions. I highly recommend electric start.
    Corvairs are commonly used and were the specified engine for all Pietenpol Air Campers after 1966. Bernie's conversion was a hand propped engine which retained the stock blower fan. Many engines were built exactly like this for Pietenpols, and some have logged well over 1,000 hours. The only case where I would use a blower fan/hand prop motor would be in building an exact replica of one of Bernie's planes. My own Pietenpol had electric start and no blower fan.
    I offer engine mount kits and complete mounts for a number of different popular airframes. Some aircraft, like a KR2, do not require you to complete the airframe before building the mount. I have a large database of completed airframe weight and balance reports which went into the design of my mount. Conversely, if you were building an original design, you might want to leave the motor mount for last.

    Subj: Prop L or R
    Date: 4/29/03

    Ordered the new Manual and the engine should be ready this year. My question is, in a pusher configuration, will I be needing a left or right hand prop? Plan on getting an in-flight adjustable. Do you think Ivoprop is my best bet?

    Know you're busy, love the magazine articles. Thanks for your time.
    T-lll by the way, wanted beta to back off the beaches down here in S. Louisiana.
    R. Giroir, T-III, La., fasteel2000@msn.com
    Reply from WW:
    Good to hear from you. Yes, if you use the engine as a pusher, you need a specific pusher prop for it. Under no circumstances should anyone use an Ivoprop on a Corvair motor. I used to be an Ivo dealer, I know their products well, and there is no Ivoprop that is structurally sound on a direct drive 4-stroke motor. There may be someone who debates this, but keep in mind, it's their words and your life. Most people survive their first engine failure in an airplane. On the other hand, losing a propeller blade in flight has much grimmer survival statistics. Beyond the fact that these props do not have any type of performance advantage on the Corvair, no one should accept the unnecessary risk of operating an Ivoprop on a Corvair.
    I understand the attraction of in-flight adjustable props, and I continuously investigate new ones coming to the market for their applicability to Corvair engines. The only prop which I believe is light enough, has an advanced blade design, a simple in-flight mechanism, and comes from a reliable, stable company, is the Hoffman. Hoffman props are made in Germany, and are frequently seen on certified motorgliders.

    Subj: Finding an engine.
    Date: 4/28/03

    Hi William, my name is Keith Smith and I'm looking for an engine to power a KR2S that I hope to start building within the next 2 years. My question is: What types of cars did GM put these Corvair engines into? If I were to look for one in the paper, what would I need to look for?

    Keith Smith, Ssmithsk3@aol.com
    Reply from WW:
    From your comments, I assume you're a member of Generation X. I myself am one of the last of the Baby Boomers and I can remember when a lot of people still drove Corvairs as a daily driver. The economics of the engine make it attractive to a lot of guys getting ready to make their first mark in aviation. You are in good company.
    The Corvair was a separate model of cars built by GM that were sold under the Chevy banner. Inside, they are truly Chevrolets in the sense that they were designed, built and sold through the Chevrolet division. If you were to run an ad in the paper, you would be looking for a 1964-69 110 or 95hp Corvair motor. These would have been installed in Corvair vans, pickup trucks, 2-doors, 4-doors and convertibles. This is just the same as the way GM made 2-door, 4-door and convertible Chevelles.
    My Conversion Manual details all the information you'll need for an effective engine search. It is available in the U.S. for $59USD by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15USD for international S&H, including CANADA).
    A couple of years ago, I drove from Florida to New Jersey and back in a friend's 1963 Corvair Coupe. The car was lowered, had wide tires on it and was painted bright red. It was different looking, even for a Corvair. I stopped in a Georgia gas station, and an 18-year-old attendant wearing a Chevrolet hat was a little puzzled as to why I was putting gas in the front end of the car. He was very curious and I showed him the engine in the back. Although he was very interested, the car must have seemed like some kind of strange import to him. He asked me, "Who made this car?" Noticing his hat, I thought he would enjoy hearing that this innovative product was made by his very own beloved Chevrolet. When I told him this, he gave me a look like I was the worst, lying, blasphemous, Commie bastard he'd ever met in his entire life. I showed him the Chevy emblems on everything, but he still wasn't convinced.

    Subj: Combustion Chambers
    Date: 4/27/03

    The Conversion Manual that I just got states "that the heads from the low compression smog 110hp and 95hp engines are NOT RECOMMENDED."

    I've not listened to Rush in many years, but he used to have a saying, "words mean things." I believe that you were stating to not use "low compression smog," be they 110 or 95, not that all 95s are bad. On Page 18 of the new Manual, you speak highly of the 95 engine. You go on to say that the 95 SMOG head has no quench areas, whereas the head in the photo in question clearly has quench. Please explain. Thank you.
    Sam Sayer
    Reply from WW:
    You read this correctly. What I'm against are heads that do not have a quench area. By far, the vast majority of 95s do have a quench area. I have built and flown numerous engines with these heads, and they work very well. Ditto for the 110 heads.
    The heads I do not like are the open chamber, no quench castings. These include the smog engines and the 180 turbo heads. These heads are rarer than people think. My guess is that they were something like 5 percent of the 110/95 production. But, I do want people to be alert for this. I personally have flown time on the wrong heads, and can assure you that they will fly and work, but they reduce your resistance to detonation. For the small effort of getting the correct heads, you can be confident of building a better engine. The photo in the Conversion Manual illustrates the sort of heads you should be looking for. For all those who do not have the latest version of the Conversion Manual, it is available for $59USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15USD for international S&H, including CANADA).

    Subj: Early Motor
    Date: 4/26/03

    My son, Chris McAtee, and I are building a TriQ and plan on powering it with a Corvair. Chris ordered your Manual and then headed off to college to let me continue working. After letting the project sit for a couple of years and waffling on the engine choice, one of my flight students, Dave Caylor, purchased a Piet with a Corvair. He showed it to a prof of engineering at our local college who then wrote you a letter that you posted on your site. Dinking around one day, I looked up your site and saw his letter. Since he mentioned that he had several running Vairs and being in the same town and having little luck finding an engine core, I e-mailed him. He promplty responded that he had just junked out a running '64 and had the engine in his way at the moment. To make a long story short, I headed out with your Manual in hand. After checking the suffix number on the case (engine complete with all fan shrouds on) and seeing the '64 sitting there (it is a "YN" number), I purchased the engine after being assured that the engine was probably the original. After teardown, the head numbers (3813516) match those of an early 102 horse and it has the wrong number on the crank. It is probably a 145 (I'll mic the cylinders on Saturday).

    Question: Is anything on this engine useable? It is in VERY good condition. Are the cases for the early YN engines the same as the 64 YN cases? If I get the stronger rods from the newer engines, will the OT-10 cam fit? Boils down to......did I spend $40.00 badly?
    Mark McAtee, TriQ, Casper, Wyoming, matee@trib.com
    Reply from WW:
    You have the bad luck to have gotten a 1961-63 engine from the 1964 car. The good news is there is certainly $40 worth of parts on the engine. The main difference between your motor and a long stroke case is a slight relieving to allow for a longer stroke crank. An hour's work with a die grinder makes a short stroke case capable of handling an 8409 crank. It is not difficult work to do. The OT-10 cam will fit right in the case. All the other stuff will bolt right to it. Chances are you'll come across a 1964-69 motor for less money than it would take to buy the crank, rods and heads separately. Either way, your $40 was a very inexpensive starting point. I don't believe anyone else in America spent $40 last week and got as many aircraft engine parts as you did.
    If anyone knows of any engine leads in the Casper, Wyoming, area, please e-mail Mark directly.

    Subj: Corvair Fold-A-Plane
    Date: 4/25/03

    Friends, We ran a short story on Steve Rahm's new single place project in the last Corvar Flyer newsletter, Spring 2003. If you'd like to take a look at a professionally designed single seat airplane for Corvair power, here's a link to Steve's site: Corvair Personal Cruiser.

    William
    Subj: UAVs
    Date: 4/24/03

    I'm doing a general survey for a large UAV company into the usability of various engines. Where can I find more technical information (Lubrication, Ignition, Weight, displacement, BSHP, FF, BSFC, etc) about Corvair engines? The Web site does not seem to list this info. TIA, Regards,

    Geraldo van den Heuij, The Netherlands
    Reply from WW:
    Although I know all the data you need on the Corvair motor, UAVs (Unmanned Aerial Vehicles) really only have two applications in practice: government surveillance of civilians and military applications. I am in no way interested in assisting anybody with the former and would only assist my own countrymen with the latter, but I am quite sure that the U.S. military has much better stuff than could ever be operated by Corvair motors. Hope you take this the right way. I'm sure somebody in your home country would respond exactly the same way if the roles were reversed.

    Subj: Thermal Efficiency
    Date: 4/23/03

    G'day. I'm an Australian living in Melbourne who has a great love of aircraft and who regulary reads the information on your Web site.

    I note that the specs on your Web site show that the Corvair, particularly the O-190, is an oversquare design (larger bore than stroke) and that you state that the engine's stroke of less than 3 inches contributes to its smoothness. I've been wondering if an oversquare design has a higher thermal efficiency than an engine with a lower bore/stroke ratio. Do you know if this is generally the case? To me it would seem to be for reasons such as:
  • the BMEP remaining higher for a greater proportion of the engine's stroke,
  • mechanical losses would be less because piston speed as a function of crankshaft speed would be lower, and
  • because the piston area to circumfrence ratio would be higher leading to lower leakage of BMEP past the compression rings.
  • If you can would you be able to confirm these ideas or put me straight if incorrect. Any assistance will be greatly appreciated. Regards,
    Andrew Patmore, Melbourne, Australia, patmore@tpg.com.au
    Reply from WW:
    Your questions indicate that you have an engineer's perspective on engines. Very rarely do we get such in depth technical questions. While there are many things in life I do not know much about, I can honestly say to you I have an unusually good background in the fundamentals of physics, chemistry and thermo. This combined with my practical observation and many, many years of reading and learning from people far smarter than myself have given me a good background from which to discuss these things.
    The main issue that you need to look at in motors is not bore and stroke, but rather the stroke to rod length ratio. Most automotive engines in America have a 1.65 to 1.75 ratio. When this ratio gets better, like toward 2:1, the piston has dramatically more dwell time at TDC. This is where really thermally efficient engines start. The down side is the piston is subjected to more brutal accelerations and decelerations. Many people look at average piston speed, but this is a meaningless number. The real issue is how steep the acceleration curve is. This is the real limit. The Corvair's rod length is about 4 3/4". Its rod ratio is 1.62:1, average for a car engine. In production engines, you'll notice diesel engines are the opposite extreme.
    You talk about a number of variables. If we were to change just one on the motor, you could easily discuss or evaluate its effect. Engines with a bore and stroke combination that produces the least surface area tend to lose less heat. This tends to favor square engines. Most people mistakenly believe that given engines of equal displacement, long stroke motors somehow produce more power, but testing reveals this is rarely so. Probably the reason most people believe this is ram tuning leading to higher volumetric efficiency requires less homework for the designer on a long stroke engine.
    Subj: Learning what's not in the book
    Date: 4/22/03

    Thank you again for your reply to the Florida Pietenpol for Sale.

    I am an ag pilot with well over 1000 hours. I have always followed the "standard" carb heat procedures without any problems. But I did not really understand the mechanics of what was taking place, because it was never explained. This rather makes me wonder if my instructors knew. Your article regarding carb icing is a real eye opener and will go with me and will be taught in all future flights. That is one of the many reasons I wish to be a Sport Pilot Instructor. An old ag pilot told me one time, "Son, learn what is not in the Book if you want to stay alive." Have a great day,
    Benny Clark Sr., Pietenpol, Texas, texaswings@cox-internet.com
    Reply from WW:
    Thank you for your complimentary comments. I believe your observation on the average instructor's understanding of carb icing is quite correct. While I was fortunate enough to have a flight instructor who understood technical issues like carb ice, I feel that there are probably many instructors who may be good pilots but don't really understand physics and chemistry. This is why Grace Ellen took the time to write the article, posted on my flycorvair.com Web site at Carb Ice. I think your instructor's thought on learning what's not in the book is very good advice. One of Grace's flight instructors always said, "Your pilot's license is a license to learn, not the end of your education." ... Solid advice.

    Subj: Zenith 701
    Date: 4/21/03

    I just purchased your Manual mostly because of curiosity, but I'll think of it more as an investment. I plan to put a Corvair on a STOL 701 (Version 4 - 1,100 lbs. gross) mainly because I see a lot of them with the SOOB power (pretty heavy when it is all added up).

    I know I am going into uncharted territory - but this IS experimental aviation isn't it? Look forward to the delivery of the Manual.
    Martin Bima, Zenith STOL 701, Winnipeg, Canada, mbima@hydro.mb.ca
    Reply from WW:
    This year at Sun 'N Fun, Zenith announced that engines the weight of an O-200, EA-81 or a Corvair are acceptable on a 701. They may have some firewall beef-up in mind, but they told a number of 701 builders that the Corvair would be acceptable. Keep in mind when dealing with Zenith that the only time they use the term "approved" with an engine is when they have personal flight experience with it. Until we're at that point, I just tell people the Corvair is within Zenith's weight and horsepower requirements. In the future, I think this will be a very popular engine combination. Previously, Zenair would tell us they wanted no more than 200lbs. firewall forward and I must have had 200 people ask me about this in light of seeing O-200s and Subarus on the 701.

    Subj: Florida Pietenpol for Sale
    Date: 4/20/03

    I am really confused. I am considering purchasing a Pietenpol located in Florida. The owner I am convinced is an honest person and has suggested that he would not fly the Pietenpol from Florida to Texas. He is not comfortable with the engine since some of his friends had an engine failure from carburetor ice and almost got killed. From the information on your home page, maybe pre-judging from others' bad experience is not the best thing, although the engine is direct drive. It has a static run up of 2600 to 2700 with a propeller designed to accomplish this RPM. And I am told this propeller and RPM will produce some 100 to 110 HP. Would you be kind enough to council me in my dilemma as to what to do??? Have a great Day,

    Benny J Clark Sr., Pietenpol, Texas, texaswings@cox-internet.com
    Reply from WW:
    I suspect you have been dealing with a man named Joseph Vince, who also calls himself "The Reverend Joe." Unfortunately, he is not an honest person. Nor is he a friend or associate of mine, and he did not convert his Corvair according to my Conversion Manual. I have personally inspected his aircraft, and can assure you that it has numerous structural deviations from B.H. Pietenpol's plans. I have seen the aircraft advertised on the Internet, and would only wish that it not bring tragedy into someone's life. Joseph Vince's engine was built out of junk parts with a very low level of knowledge, craftsmanship and care. The fact the engine failed on its first flight came as no surprise to people who had seen the aircraft in person. The real surprise was that Joseph, who purports to be a man of God, would talk someone else into flying the plane for him. I bear no malice against this person, but I cannot understand his actions, and I know aviation, the passion of my life, does not need another black eye.
    Under no circumstances should anyone purchase either Vince's "Pietenpol" or his "engine." Neither are airworthy for a multitude of reasons.
    I did get seriously injured while riding in my Pietenpol as a passenger. After the engine went out due to carburetor ice, the pilot spun the plane in from about 80'. The full story is on www.flycorvair.com at the page titled Carb Ice. Following the number one rule of FLY THE PLANE, would have prevented this, as would have checking the weather, pulling on the carb heat knob which was located at only the pilot's controls, installing a carb heat knob in the front cockpit, being more selective about who I let fly the plane, etc. As long as you are a diligent pilot, this kind of accident will never happen to you.
    My standard suggestion is convert the engine yourself according to my Conversion Manual, build the plane yourself according to Bernie Pietenpol's plans, and learn to fly for yourself with a competent instructor. You will enjoy both peace of mind and pride in workmanship if you trust in and rely upon yourself, and ask questions without hesitation when you need a little extra help.

    Subj: Corvair Fuel Pump
    Date: 4/19/03

    I visited your Corvair presentation at Sun 'N Fun. Do you know that there is an AD note on all Franklin engines using the diaphragm type fuel pump? This happens to be the same fuel pump used on the Corvair motors. I don't know what the replacment would be as it didn't specify in the AD. I haven't had any trouble with the one in my Corvair. What's your take on this.?

    Bob ODell, Panacea, Fla., Lledobob@aol.com
    Reply from WW:
    You are quite correct that certified Franklin motors were delivered from the factory with Corvair fuel pumps. Several years ago, there was a fatal accident in Texas in a Franklin powered Swift that utilized this fuel pump (I am pretty sure there has never been a fatal accident in a Corvair powered aircraft). You can read the accident report on the Web at www.faa.gov, and there are a number of other factors involved besides the fuel pump. Franklin engines are made in Poland, and the American fuel pump manufacturer may have been a more tepmting litigation target. As a result of a lot of litigation, etc., there is now an AD. So that everyone understands, ADs only apply to certified aircraft. My personal experience with Corvair fuel pumps is that they are reliable and when they quit, they give fair warning. If they have been less than reliable in Franklin engines, it probably has something to do with that installation or perhaps their overworking it to feed a 220hp engine. I would not be very concerned about using it in its stock Corvair application.

    Subj: Parts
    Date: 4/18/03

    Weíre finally getting around to building our engine and need a few parts. The guy we bought the engine from did a great job except that he spent a lot of time putting a magneto on it. Iím not sure why he didnít get the performance out of it that he expected:) We need the rear housing, oil filter adapter plate, by-pass valves and one of your dual ignition distributors. What all comes with the distributor - cap, rotor, re-curving? Know anyone who wants a magneto for their Corvair engine?

    I have to warn you, dad met you about a year ago in North West Florida at a small EAA fly-in. He says that he has several questions for you??? Should be interesting.
    Iím building a Vision and stopped by in November to see Steve. We walked all the way over to your place but you were out, sorry I missed you. Thanks,
    Brian, Vision, brianyoung@charter.net
    Reply from WW:
    Sorry we missed you. We spend about 100 days a year on the road. If anyone is planning on a visit, please call in advance. We've had hundreds of visitors to the hangar over the years, and you're always welcome.
    Undoubtedly we met your Dad at the Quincy Fly-In near Tallahassee, Fla. We had a great time there, and there were a lot of very mechanically clever guys, typical of many rural areas in America. Certainly e-mail any questions your father has.

    Since you have my Manual, you know my experience and opinion with magnetos (great for certified motors, not appropriate for Corvairs). Please note that my dual ignition distributors are now completely re-manufactured in house and contain everything from the bottom of the shaft to the top of the cap. You need only send us your old core and a check for $219 payable to William Wynne, 210-11 Cessna Blvd., Port Orange, FL 32128 (add $15 for international S&H, including CANADA). These are also available by credit card via PayPal at the Online Catalog.

    Subj: Corvair in Merlin
    Date: 4/17/03

    I'm looking at purchasing a Merlin kit (without Rotax) & have been eyeballing the Corvair. Do you know of anyone who has used the Corvair in a Merlin?

    Doug Baird, DBaird@barroncollier.com
    Reply from WW:
    I do not know of anybody who has used a Corvair in a Merlin. The Merlin is a fairly efficient airframe in its class, and reported to be a very sturdy design. The Corvair has very successfully powered a number of aircraft in the Merlin-size category that were substantially less efficient. If you can get a report from somebody flying a Merlin on an O-200, this would give you a good indication of its performance with a Corvair.

    Subj: Engine for Zodiac 601HDS
    Date: 4/16/03

    I have finished most of the airframe on my Zodiac and am looking for an engine. I bought a Subaru EA81 at a junkyard, but after looking at the cost of a PSRU and other expenses to get ready, I am about to change my mind. I am interested in a Corvair and thought I would check the availability of one in my area (Western Kentucky) but wanted to ask your opinion on which engine would be best suited for the 601, a 164 or 190? If I go this route I'm sure I will be buying your Manual and some parts. Thanks for your help.

    Mark Sandidge, Zodiac, Madisonville, Ky., MSandidge@PeabodyEnergy.com
    Reply from WW:
    Thank you for going ahead and buying the Manual. While your questions will be answered in the Manual, available for $59USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15 for international S&H, including CANADA), let me share the answers with other readers of the Web site. While I am emotionally biased toward American products like the Corvair, the factual numbers bear out that the Corvair, even the standard 164cid power plant, will be a better power plant for your 601 than the EA-81, even with an expensive PSRU. My opinion on this is based on replacing flying Subarus with Corvair engines in two KRs and a Stits Skycoupe last year. The KRs were much lighter with direct drive Corvairs, and had better performance with far more conservative use of the engine. Notably, each of these engines was built for less money than the PSRU cost for their respective EA-81s. Corvairs can be found in every part of America. Most guys spend less than a week looking for one after they decide to build.
    I'm working with a number of 601 builders to produce drawings and parts to make your engine installation simpler. This is high priority for me, and you can expect to see things like the motor mount soon.
    The direct drive, air cooled simplicity of the Corvair is much more complementary to the 601, which has the same values of simplicity and reliability.

    Subj: Piet Corvair
    Date: 4/15/03

    I am just starting a Piet (ribs built, moving on), and I am interested in a Corvair for power. When is the next "Corvair College" scheduled? And are previous "College" pictures, tapes or whatever available?

    Daniel Bailey, Pietenpol, EAA 96269, Chapter 868, Olathe, Kansas, dbceltic@micoks.net
    Reply from WW:
    We just had Corvair College #4 at Sun 'N Fun 2003. At this College, I introduced the first tape in my engine building series. It is available for $29USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15 for international S&H, including CANADA). The second tape in the series is being edited now, and the third will be done by Oshkosh. While I'll be speaking at Brodhead and Oshkosh this summer, I have no firm plans to hold a College at either location. I have traveled to Kansas several times to promote the Corvair motor. In the past, we've attended the Tandem Wing Fly-In in Ottawa, Kansas, and demo pilot Arnold Holmes operated my Pietenpol out of Gardner, Kansas, for a month in the Fall of 2000. Perhaps you remember seeing it.
    The Corvair and the Pietenpol are a natural combination. Remember, it was the specified choice of Bernie Pietenpol.

    Subj: Corvair forums at Oshkosh
    Date: 4/14/03

    I had met you at Sun 'N Fun but hadn't attended your rebuild sessions. I'm wondering if you're going to be at Oshkosh this year. Please let me know. THANKS.

    John, jcl64@a-znet.com
    Reply from WW:
    I will be giving forums at Oshkosh 2003 for my second year in a row. Check back at the AirVenture 2003 Forums Page and the News from the Corvair Authority Page on flycorvair.com for the schedule as it becomes available.

    Subj: WOT Fuel Flow
    Date: 4/13/03

    Have you tested a Corvair to run all day wide open, 3200RPMs? What is the fuel flow on the big O-190 WOT? Has anyone ever put fuel injection on these? It seems like a good idea fuel injected since the need for a fuel pump on my plane is already there.

    Justin, jmw116@socal.rr.com
    Reply from WW:
    The longest length of time I've operated a Corvair motor at WOT was 2 1/2 hours at 4500rpm. After a 5 minute break to refuel, it did another two hours at the same output. The Corvair motor ran at more than 3200rpm at highway speed in the original car. The engine is not bothered by any rpm that you would find useful in a direct drive engine. Fuel flow at any power setting is directly related to the amount of power developed. A Corvair motor, like almost all others, burns .5 pounds of fuel per horsepower per hour. Thus, 100hp continuous output would be 50lbs. of fuel, which is 8.3 gallons per hour. Please note that very few aircraft engines, even certified ones, are operated at WOT all day long.
    I have done work on some of the most sophisticated aircraft in sport aviation. I have experience with the fuel injection systems on these engines and it is my opinion from experience that virtually all homebuilders would be better served with a carburetor. Fuel injection is covered in several pages in my Conversion Manual, available for $59USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15 for international S&H, including CANADA). In short, the claims of great fuel savings will never materialize, and the complicated electronics, their high power consumption, single point failure modes, 35psi fuel systems, etc. are an entirely different category of aviation risk management. If you really want to go flying, build what experience has shown to work and let craftsmanship be your personal mark on your aircraft.

    Subj: Getting Started - EAA Experimenter March 2003
    Date: 4/12/03

    I just wanted to thank you for writing the article, "Making the Decision to Build Isn't Easy or Rational," in the March 2003 issue of EAA's Experimenter magazine.

    For several years I have been "struggling" with all the reasons why I wanted to build an aircraft, and also, with equally valid reasons why not to. I, too, had been trying to "rationalize" my feelings towards this project and getting nowhere. Not being able to verbalize my feelings to my family and friends did nothing to help my cause. After reading your article, I immediately understood that my reasons for building were more deep-seated than I had originally thought.
    I have just returned from Sun 'N Fun. There, while speaking to homebuilders about their projects, I couldn't help but notice similarities in their expressions and passion in their voices when they spoke about the "building process." I will assume, since the results of their labor was sitting right in front of us, they used this passion to see them through to completion. Another common thread was the pride they felt when they took flight in their labor of love. Frequently, they would punctuate their sentences with phrases like, " . . . I've never regretted it . . .," or ". . . this is my lifetime achievement . . . ".
    Your article helped me understand that my passion to build is tied more to a combination of my love of flying and my need for a creativity outlet rather than simply the need for an aircraft. I've removed the "no rational reason to build" entry from the "minus column" and happily added the entry "outlet for creativity" into the "plus column."
    Thanks again for a great article. Best regards,
    Stuart Heitshusen, Schenectady, N.Y.
    Reply from WW:
    Thank you very much for your kind words about my column in the Experimenter. Mary Jones, the editor, asked me to write a continuing column specifically aimed at the person who is a first time builder, just like you. Her request reflects EAA HQ's emphasis on including all people in homebuilding, not just the most financially fortunate. I tried to address the most common concerns and issues which first time builders face, for I myself went through this process just like you.

    Subj: Engine Block Suffixes
    Date: 4/11/03

    I spoke with you at Sun-N-Fun (with about a million other people!) and got your Conversion Manual. I have obtained enough parts to start building an airworthy engine BUT...my block has suffix letters RN. This is not posted in your book and I am wondering if I have a good block? Incidentally, the guy I bought the pieces from showed me a factory publication and there are a LOT of designations that aren't reflected in your Conversion Manual. It's probably not a big deal, but I rely on your experience and this one is a stumper.

    Larry, lnawms@msn.com
    Reply from WW:
    Your RN motor is a 1965-66 140hp Powerglide equipped engine. The only parts of this engine which are not suitable for use on your conversion are the cylinder heads and the 4 degree retarded crank gear. The good news is that the crank gear can be replaced with a new one for about $85, and the cylinder heads are worth up to $300 for the pair to a car guy. The much more common 110 cylinder heads are the ones you want. They are much cheaper, and will bolt right on to your cylinders. Other than this situation, which precludes its inclusion in the Conversion Manual, your motor is an excellent core.

    Subj: Carburetors
    Date: 4/10/03

    In your Conversion Manual, you speak of MA-3 and MA-3SPA carbs costing upwards of $500. In my search so far I have been unable to find one for even close to this price. Where have you seen such prices?

    Gordon Alexander, Shakopee, Minn., gordon@curio.com
    Reply from WW:
    At Sun 'N Fun I saw 20 of these carburetors for sale for less than $350. The Fly Mart had a shelf of them with an average price of $300. These are very common carburetors, as they were original equipment on O-200s. $300-$350 is fair for a good working one with a metal float (MF will be stamped on the data plate). I would pay $500-$700 for an overhauled one as long as it came with a yellow tag from a repair station. I've also purchased them off eBay and Barnstormers.com.

    Subj: Zenith 601XL Engine Costs
    Date: 4/9/03

    Am about to build a Zenith 60XL and am very seriously considering engines. I have 2 engines sitting, a 110 and a 140 hp. Are any currently flying on the 601? Could you get me in touch with the builder? Am also curious if you would be willing to supply me with cost for a conversion that I might do and give me a cost for you to build to 120 hp with electric start, 20 amp alternator, dual ignition, starter solenoid, exhaust... and let me know about engine sensors that you might think useful... I'm looking for a bullet proof and reliable engine with a long life... Thanks,

    Jim, Zenith 601XL, jdankochiro@yahoo.com
    Reply from WW:
    The 601 and the Corvair are a very good match. A number of people are working on it right now, and we're helping them develop the installation, but no one has flown the combination yet. Considering the engine's success in other airframes, no one should have any doubt that it will produce a very economical and useful engine option for the 601.
    As for your request for a price quote on a motor, all of my work in the past 8 years has been primarily in the area of teaching people how to build their own motors. Although I have built many, many motors, the primary aim of my work is to help homebuilders by the original EAA motto of "Learn, Build and Fly." Your typical Corvair conversion costs $2,500 to $3,000 complete. A large displacement motor like the one you mention would be more than enough power for the most ambitious aims of the 601. The parts to build such a motor would be worth something in the range of $4,000. If I were to build such a motor, and supply it with every bracket painted, every piece of safety wire in place, etc., it would become much more expensive than the bare parts would cost you. I'm a very skilled A&P mechanic, and around here, we can bill our time for a fair rate. More importantly, in the length of time it would take me to build your motor, I could help half a dozen guys build their own, answer a few dozen e-mails, write a magazine article, make a housecall to a guy who's ready to fly, and speak to an EAA Chapter or two. Years ago, I was very thankful to anyone in aviation who wanted to take the time to teach me something. These days, given the option, I will always choose to spend my time teaching and sharing. Aviation already has too many expensive engines for people with thick wallets. I would much rather have you be one of the six people who comes away with the positive experience of saying "I built my own motor, learned a lot, saved a bundle, and have a real experience to be proud of."

    Subj: 1/2 Corvair! Is This Possible?
    Date: 4/8/03

    I saw a 3 cylinder 1/2 Corvair in a 1978 Sport Aviation. Is this a hoax? Would it really run?

    Micheal J. Fox RN, BSN (Not the Actor), foxyrn@usa.net
    Reply from WW:
    The 1/2 'Vair is not a hoax, but it doesn't work either. As you may guess, I found it in a Corvair car collection about 7 years ago. It was built less than 10 miles from here. The engine had to be the work of two people: one good, the other a hack. But neither of them knew much about balancing motors either. It would run very, very rough. It would also have 70% of the weight and 50% of the power of a full one. Sure does look nice though; it is a more appealing shape than a 1/2 VW. But it will not work because the opposed motor counts on the mass of the piston and rod on the other cylinder for balance.

    Subj: New Video
    Date: 4/7/03

    William and Grace Ellen,

    I received the new video on Friday, but the ice storm in the Detroit area kept our power off until late Saturday. I found the video very helpful in understanding how a Corvair motor goes together. There are so many differences between a flat engine and that of a standard V configuration. They say a picture (or video) is worth a thousand words, and it's true. I've read the Chevy manual and Finch's book, but it was William that took me through the steps required to assemble the short block. Now I understand! Great job!
    I have just joined the local Corvair car club and am making the contacts required to locate the correct engine. Will there be an "Engine Assembly Part 2" video? I plan to attend Oshkosh this year and my first stop is to buy both of you a couple of beers. Unless, of course, William would prefer something with an umbrella in it! :-) Just kidding! Thanks for all your help,
    Jim Burt, Manual #5301, jim.burt@gm.com
    Reply from WW:
    Thank you for the nice words about the Engine Assembly Part I Video. We have these readily available for $29USD by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15 for international S&H, including CANADA).
    Although we just introduced these three weeks ago, a lot of positive comments like yours have come back. We have already filmed Part II, and it will be available next month. Part II is pistons, cylinders, rings, rod bearings, etc. Part III, which is only scripted at this point, is going to be the cylinder head and valve train video. These will be done for Oshkosh. We also are kicking around the idea of an engine teardown video starring Grace Ellen. If you have other ideas of what you'd like to see, please let us know.
    We'll definitely be at Oshkosh, and we'll definitely take you up on your offer. Watch the EAA AirVenture 2003 Forums Page and News from for the Corvair Authority Page on flycorvair.com for the forum schedule as it becomes available.

    Subj: Corvair Head Numbers
    Date: 4/6/03

    I recieved your Manual and video this week and have been pouring over it! I have 3 blocks: 1 with a ZF code, and 2 with the YC code. According to the Manual, these are the 95 hp engines. The head numbers I have been able to read are not on your list. They are 3813516, 3813513, 3786589 and 3786752. Will I be able to use any of these heads in my Pietenpol? I'm looking forward to getting started on my projects and enjoyed your presentation last summer at Brodhead. Maybe I'll see you there again some time. Thanks,

    Dale Haag, Pietenpol, West St. Paul, Minn., haagc@uswest.net
    Reply from WW:
    The engine letter codes you mention could either be an acceptable motor or non-acceptable motor. Letter codes like ZF and YC are only acceptable when the motor is a 1964 model. These same letter codes were also used on earlier engines. Your cylinder head numbers are all from early engines, so I suspect that your engines may be short stroke engines. A careful review of the Conversion Manual will show you that you need to check the crankshaft for the 8409 stamping. The head numbers you mention are not listed in the Manual because they are not acceptable. If your crankshafts have any number other than 8409, they are unacceptable.
    Thank you for the kind words about Brodhead. We're looking forward to going back this year.

    Subj: Midget Mustang Corvair
    Date: 4/5/03

    How does the Midget Mustang fair with a Corvair conversion?

    Dennis Lithgow, Midget Mustang, denbeclithgow@juno.com
    Reply from WW:
    The Midget Mustang is a beautiful and also highly efficient airframe. Our friend Paul, who's at our home airport of Spruce Creek, is working on this same combination. I've studied the horsepower requirements, firewall size and shape, and the standard cowling, and feel it would be a good match. We have a dummy engine in Paul's cowl now, and are working on a motor mount for him. Watch www.flycorvair.com for details.

    Subj: Static vs. WOT RPM
    Date: 4/4/03

    What kind of increase in RPM do you see between static and full throttle level fight? Say that 72" Warp Drive prop on the ground run 2650rpm, what would we see in the air on say my gyro? Or what did you see with the 68" Warp Drive on the Pietenpol?

    Brent Brown, Autogyro, Fayetteville, N.C.
    Reply from WW:
    A Warp Drive with the correct pitch setting for cruising at 85mph will turn an extra 150rpm or so in level flight over what it did on the ground. If the airspeed was, say, 150mph, I believe the difference would be substantially greater. The longer Warp Drive props will flex somewhat in operation and contribute toward smaller rpm variations.

    Subj: Rear Mounted Starter Kit
    Date: 4/3/03

    What is the estimated cost of a rear mounted starter kit? Thanks!

    Clint Courtney, Troy, Mo., can3g@aol.com
    Reply from WW:
    Here's a brief history of starters on Corvairs. Prior to my work, virtually all Corvair motors were hand prop. Eight years ago, I developed a front starter setup and sold parts and plans for it. About four years ago, there was talk of developing rear starters. As far as I know, I was the first one to fly one on the back of the motor and fully investigate all of the oil system modifications, etc. After having built and flown several versions of each system, it is my opinion that my current generation of front starter systems is the better way to go. Most of the people interested in the front starter system simply say, "Good, I like it. Show me how to make it or sell me one." Conversely, most of the guys working with rear starter setups all want me to change the design or modify it slightly to fit each of their individual aircraft or separate needs. Thus, it's not economical for me to produce parts for rear starter systems.
    The Conversion Manual, available for $59USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15 for international S&H, including CANADA), contains the complete story for starters at both ends along with my complete experience developing and flying both. But, I only offer parts for front starters, and the complete story on my latest update on front starters, including simplified bracketry and much lower profile, is included in the Spring 2003 edition of The Corvair Flyer newsletter. Annual subscriptions are available for $20USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $5 for international S&H, including CANADA).

    Subj: Corvair for Europa
    Date: 4/2/03

    I am building a Europa XS, it needs about 120hp for T/O with a FWF of 200lbs approx. Do you know of any Europa builders using the Corvair? The single ignition worries me, can dual plugs be fitted to the heads, and maybe a magneto to fire them, or even the HEI from the Chevy V6? Is the 3100cc engine not as reliable as the 2700cc version, if not then why use the smaller engine for the same weight? I believe that the max bore is 94mm - can the engine be stroked for more cc? I have used 100mm cyls in a Type 4 VW - has anyone tried these in a Corvair? I'm seriously looking at the Corvair for my Europa, and your engine conversion looks a strong contender. The requested info, and any comments would help me decide. Thank you in advance,

    Dave McCandless, Europa, daval@iprimus.com.au
    Reply from WW:
    You certainly take the award for packing the most questions into a single e-mail. All of your questions are answered in depth in the Conversion Manual, available for $59USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15 for international S&H, including CANADA).
    But let me give you a quick overview. 3100cc Corvairs cost about $800 more to build than 2700cc Corvairs. Additionally, they take a little more care and require a better than average core motor to begin with. The reason why 95% of Corvair builders are going with the 2700cc motor is that it makes excellent power very economically.
    Corvairs can be stroked and bored beyond 3100cc, but this requires extremely extensive machine work, and it would be much simpler and probably less expensive to go with another type of motor, especially since you're in Australia.
    On your ignition worries, my dual ignition system with single sparkplugs has been proven in hundreds of hours of flight use. My aircraft's first 300 hours of operation were with dual plugs with one set driven by a magneto. Dual plugs is a worthless modification of the Corvair cylinder head, which causes an unnecessary loss of cooling fins. In hundreds of hours of flying Corvair motors on a variety of fuels, I have never fouled a sparkplug. This is very likely due to the fact that the Corvair does not leak oil into the cylinders, has a very strong spark at idle (unlike a magneto) and it has high enough compression to have efficient combustion. As for reliability, electronic ignition systems like the HEI work great for a long time, but fail without warning. Although points will not last as long, they almost always give plenty of warning. This alone makes them superior. Anyone who is critical of points ignition should realize that all aircraft magnetos have points inside.
    Several years ago, Europa Aircraft claimed their aircraft would do 200mph on an 80hp engine. The most modest Corvair motor can easily exceed this at very conservative rpm.
    Les VanMeter of Chino, Calif., is our leading Corvair/Europa builder. Perhaps you can contact Les through the Europa builders network.

    Subj: Cabin Heat
    Date: 4/1/03

    I have a quick question: Is it an easy matter to install heat into the cockpit with the Corvair engine? Maybe thru the oil cooler? I have have not ordered your book but plan to right after April 15th. Thank you.

    Mike, gbgroupmike@hotmail.com
    Reply from WW:
    The issue with oil for cockpit heat is this: When the weather gets cold enough that you would need cockpit heat, the oil cooler no longer runs hot enough for a good supply. A cabin heat muff off the exhaust system would be the best way to go. Just make sure you have a very good exhaust system and a CO detector inside the plane. Virtually all certified aircraft are done this way, and with good annual inspections, it is a safe system.

    Subj: Stock Linkage
    Date: 3/31/03

    In all of your travels and purchases, do you run across 140 stock linkage? I am looking for a useable set. From reading your info, it looks like you go to a different induction system. Can you help? Thank You

    Wade Williams, Wade@DRC-ENG.com
    Reply from WW:
    My friend Kevin and I own a number of Corvair automobiles. The one characteristic they have in common is that they are all 140 powered. Even Kevin's shortened 1962 Monza convertible has a 140 Powerglide setup in it. When we come across good 140 stuff, we tend to put it to good use ourselves. The carburetor linkage, as you know, is much rarer than the heads. Perhaps someone reading this on the Q&A Page could help you out? Hope it works out for you.

    Subj: Pietenpol Update
    Date: 3/30/03

    Just a note to update the Pietenpol Corvair rebuild. We are at the cooling duct stage and had them all fabricated when we discovered there was very little access to the spark plugs so started to make access doors with Hartwell latches.This failed because the material was too light and they wouldn't close tightly. We solved the problem by fastening the covers with P K screws. Also making cowling openings bigger with a duct tube from the center to the oil cooler on the firewall. Note: Old distributor to be used for pre-oiling and all the clutter in our shop. An old mechanic told me one time that you could tell if the work was getting done by how the shop looked. If it was squeaky clean they weren't doing anything. The weather will govern the installation on the airframe but we are almost ready. More later if you like.

    Ray and Rich Hill, Pietenpol, Baxter, Iowa, raydot@pcpartner.net
    Reply from WW:
    Thank you for the update. Yes, please make sure you send us more pictures as it comes along. Sometimes the simplest solution, i.e. PK screws, is the best.

    Subj: Pegazair on Floats
    Date: 3/29/03

    I received and read your Conversion Manual yesterday. Thank you. After reading that and several of the other builders' Web sites, I have found that I'd like to spend the money and have the 3,100cc modification. I say this because the weight and power advantages are worth the $1,500 to me. I also have come to see the light about going direct drive. Other features I find appealing are: no blower, the OT-10 Cam, your oil pan, a snap ring retainer if possible, a Supertrap muffler if possible, electric start - probably front, and mounting as large a Warp Drive two blade as you'd recommend.

    I live on a lake and expect fly my Pegazair on floats. I am not sure the 100LL will often be available. I am willing to spend up to $100 per further pound saved on my engine installation if you have any recommendations on how to do this. I may also wish to try an inflight adjustable propellor at some later date, so anything I can do to help accommodate this would also be of interest to me. Is this a reasonable path? Do you have any further suggestions? Thanks again,
    Gordon Alexander, Pegazair, Shakopee, Minn., gordon@curio.com
    Reply from WW:
    I've recently tested 2-blade 72" Warp Drive props, the largest diameter they make. I have very accurate hydraulic thrust testing equipment, and the motor on the test stand was able to pull 385lbs. of thrust at 2,650rpm. Notably, the prop wasn't that loud. While 385lbs. may not sound as high as some other unobserved claims, keep in mind this is through a muffler and cast iron exhaust manifolds with no cowl, a blunt air scoop and the 32"x30" firewall on the test stand behind the prop. This is also a 2700cc motor. I would not be surprised if a 3100 inside a cowl with a less restrictive exhaust system could pull 550lbs. static. A video clip of this test is on my current video tape, Corvair Engine Assembly Part I, available for $29 in the U.S. at the Online Catalog, or by check or money order payable in USD to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802 (add $15 for international S&H, including Canada).
    Your engine proposal seems well thought out and straightforward. I'll be glad to help you out with the conversion parts as you need them.

    Subj: Best Day for Sun 'N Fun?
    Date: 3/28/03

    I plan to attend one day at this year's Corvair College at Sun 'N Fun [full schedule at News From The Corvair Authority]. I have my engine prepped and I think it's ready for assembly. What day of the week do you think would be best for you? I would also like to know if you got the new top plates in and how much they are priced for. Thank you,

    Larry Hudson, indyannie_1999@yahoo.com
    Reply from WW:
    I'd say hit the ground running opening day, April 2. Thursday, April 3, probably will be a good day, too. Look for the crowds to really start rolling in Friday. With this year being the Centennial of Flight, crowds of up to 1 million are expected at Sun 'N Fun.
    The new top plates are done and beautiful from the hydro-cutter. We have about a dozen left at the introductory price of $59. You can see yourself in the polished versions, but they're very versatile as you also can paint them or emblazen them with your own personal logo. I couldn't be happier with the final product - it was well worth the wait.

    Subj: Hello
    Date: 3/27/03

    I just thought I would update you on my KR. The stub wings are complete as is almost everything else on the fuselage. I do have to make a rudder and elevator to finish the fuselage. Oh yeah, a cowl too. I have reinstalled the Corvair engine for the last time (I hope). I have also fabricated and installed an air scoop so I can get some serious run time in on the engine. I plan to put a lot of time on the engine this coming weekend as the temps here will be hovering around 50 degrees. Who knows, I just might put fluid in the brake system and go taxiing out in the cul-de-sac. Wouldn't that raise some of the neighbors' eyebrows! It is time to get some more serious building done so I can be airborne by next fall. That is my goal. I will be at SnF on Saturday the 5th and will see you there.

    Mark Jones, KR2S N886MJ, Wales, Wisc., flykr2s@wi.rr.com
    Reply from WW:
    Thank you for the great progress report. This is the kind of news that gets guys motivated to get going in their workshops and build. You have come a long way since we visited your place last summer, and we're just as proud as you are, if that's possible. If you take to taxiing the streets of Wales, be sure you have a photo crew following you. You don't get to see that every day. Please bring all the photos you can to Sun 'N Fun. Saturday, we start out at the Engine Building Tent at 9 a.m., move to the Contact! Forum Tent #3 for William's Corvair forum 10-11 a.m., then back to the Engine Building Tent. I believe the night airshow is Saturday, so you picked a good day to get to Sun 'N Fun. We're all looking forward to seeing you there. Have a safe trip. Grace Ellen.

    Subj: Wrong engine
    Date: 3/26/03

    I purchased a 110HP engine with the wrong letter suffix (RW). Are any of these engine parts usuable? I only paid $75.00, so it seemed worth it just in case. This is a running engine. Thanks.

    Tom Wilson Georgetown, Zodiac 601HD (plans), Maine, twilson@clinic.net
    Reply from WW:
    Your motor, an RW, is a good deal for that price. It is a 1966-68 110 automatic motor. It had a factory option called AIR (Air Injection Reactor), which is an emissions control system that generally has the undesirable open-chambered heads. But, all other parts on the motor will be acceptable to rebuild for flying status.

    Subj: Corvair conversions for which planes?
    Date: 3/25/03

    I am very much interested in getting myself a small Corvair airplane to fly up north and keep on my own land. However, I need to find the correct plane for my purposes. I really like all the info you put out on the Corvair engine, especially the part about the dual points distributor and fuel pump. This is one of the main reasons I considered the Corvair engine. Because my plan is to also have a back up coil, and also backup electric fuel pump, along with a small plane parachute. Just for added precautions. But I need a lot of help getting started and need some good advice from you. I would prefer the plane to hold two average size people and obtain approximaely 5 or 6 gph, probably 20 gal fuel capacity, and cruise comfortably at 100 mph or thereabouts. Is all this possible with the Corvair or am I way out of line? I also have to consider the cost of such an adventure, because funding is out of small wallet. But perhaps you can be of a lot of assistance. Probably just another impossible dream of mine, but I think it would be fun to try. Thank you for your time, s ir. Sincerely,

    Michael T. Burke, St. Lawrence, Mass., Twofirst1@aol.com
    Reply from WW:
    There are a number of aircraft that would meet your description. Our friend Dave Vargesko is building a Wagabond (an experimental PA-17) with a Corvair motor. He will have less than $8,000 in the completed airplane. He's a fairly good scrounger, but anybody could duplicate his efforts for $10,000-$11,000. This plane will certainly do 100mph at 5 or 6 gph. Additionally, since it is a high wing aircraft, it will need no fuel pumps at all. If you fly over inhospitable terrain, or wish to reduce your risk, you should fly airplanes with stall speeds below 50mph. There are a number of other designs that would also meet your needs. The EAA's Aerocrafter guide, available at the EAA's online store at www.eaa.org, is a good place to start your search. Thank you very much for the nice words about my work.

    Subj: Pietenpol Motot Mount
    Date: 3/24/03

    I have been looking at the Manual trying to figure out the motor mount. Could you tell me some of the dimensions from your Air Camper? How far out from the firewall were your rear mounting holes? How far down from the top longerons was the bed (or thrustline)? And did you have to tilt the wing back?

    Trying not to reinvent the wheel, Thanks,
    Malcolm Morrison, morrisons5@adelphia.net
    Reply from WW:
    My Pietenpol had the short 1933 fuselage. The cabane struts were vertical. The empty weight of the plane was 732lbs., measured on electronic scales. It had a full electrical system, brakes, tailwheel, etc. The distance from the firewall to the rear bolt hole was 15". If you are building a newer fuselage, this will be several inches less. I highly recommend the longer fuselage. When my plane was painted orange, the thrust line was in the stock location. When it was blue and silver, I built a new mount which moved the thrust line up to be in line with the top longeron. It flew slightly better that way, and I think it looked a lot better.
    There's a lot of talk in Pietenpol circles about moving the wing back and forth. This is a dumb idea. With the wing moved forward, remember the landing gear doesn't move, and you're creating an airplane prone to nose over. With it moved back, you can inadvertently change the angle of incidence. The preferred method is to build the plane with the correct landing gear/wing orientation and build the motor mount to give you the correct CG with an appropriately weighted pilot in his seat. We set this perfectly when I built the second motor mount. With a 150lb. pilot, the CG was at 15"; with a 300lb. pilot, the CG was at 20". The axels were at the leading edge of the wing. The plane had excellent ground handling and flew well.

    Subj: EAA
    Date: 3/23/03

    I just read your article in the February issue of the EAA's Experimenter regarding "Resources for Builders and Pilots," and found it very informative. Happily, I have several of the essential books, and will look into obtaining the rest.

    I see that you were president of the EAA Chapter in Daytona Beach. I have just been accepted into the ACET program at Embry Riddle for next January, and will be moving there as soon as I can close on the house I've just bought. I've been a member of EAA for about a year now, though not terribly active. I mostly just read the magazines and dream about building my own airplane some day. I have one degree from Riddle already, Air Science, with the associated commercial/multi/intstrument license.
    I'm looking forward to becoming involved more with EAA and will look you up when I get myself established in Daytona. Take care,
    Marty Dudeck, 688380
    Reply from WW:
    Definitely look us up when you get to town. We'll be glad to have you over any time we're in town. Thank you for the kind words. I can't recommend highly enough joining the EAA and utilizing all its resources for homebuilders, including Experimenter magazine.

    Subj: Parts Prices, Hi Tech pistons
    Date: 3/22/03

    I need some parts from you. If you send me the cost of them, I will get a check in the mail to you. I need an Aluminum Oil Pan, some Hybrid Studs, a Distributor with the necessary work done, Motor Mount Tray and Prop Hub. I thought I could have you bring these things to Sun-n-Fun, but now I don't think I will be able to be there.

    I have the motor disassembled and partially cleaned up; it is scary to start ordering parts for the first one you work on. I contacted Clark's with their c2q form for suggested parts order, but haven't heard back yet. Their catalog boasts the quality of their Hi-Tech pistons - what do you think compared to Forged? Thanks,
    Dick Van Fossen, evanfossen1@juno.com
    Reply from WW:
    Good to hear from you. The prices you requested for these parts include S&H within the U.S.:
  • Aluminum Oil Pan: $269
  • Hybrid Studs: $66
  • Remanufactured Distributor: $219 plus your old core
  • Motor Mount Tray and Spools: $149
  • Prop Hub: $319
  • You can send a check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or pay by credit card via PayPal at the Online Catalog.
    The 2002 Conversion Manual [$59 in the U.S., also available at the Online Catalog] contains a detailed dissertation on cast, forged and Clark's Hi Tech pistons. In brief, we only use forged pistons in flight motors. The qualities that Clark's touts are true for cars, just not for planes where ultimate strength is our bottom line requirement. I understand the concern associated with jumping into your first motor. Study the Manual, familiarize yourself with the parts and don't hesitate to ask questions. We now have a very detailed video on how to assemble the shortblock. It's 84 minutes long, and we're going to have more in the series to complete the entire engine assembly.

    Subj: UP AND RUNNING!!
    Date: 3/21/03

    Happy Happy Joy Joy, It's running smooth. They just don't run when the distributor isn't installed correctly. I chewed my nails all day waiting to get home and try the starter one more time. Two squirts of starting fluid and it came to life. It took care of the clock, pictures, stepladder, and stereo in the garage, but that's a small price to pay for 10 month's work. You should know it gets a little breezy at 1500 RPM in a small room. Oil is about 40psi at 1000 RPM. I haven't checked the head temp yet, but after the first half hour I could still lay my hand on the valve covers. Thanks For The Help. I'll Be Back In Touch Very Soon.

    Jeff Kidwell, Hopewell, W.V., whenboy@shentel.net
    Reply from WW:
    Congratulations! You've worked hard for this feeling of satisfaction, and it's all yours. Looking forward to hearing more good news when you put this engine to work.

    Subj: Composite Material
    Date: 3/20/03

    Thanks for your hospitality when I drove Steve Megill and the guys up. I enjoyed talking about your twin engine design and would like to ask a question. What is the source for that sandwiched fuselage material? Thanks again,

    Dick Ripper , EAA 517011, Lakeland, Fla., rwripper@prodigy.net
    Reply from WW:
    Good to hear from you. It's always a pleasure to have Steve around, and we're glad that you and the gang from EAA Chapter 229 were able to accompany him over for assembly of his shortblock.
    I'm answering your question here because I've been getting it a lot since we featured the "Wynne Twin" in the latest Corvair Flyer newsletter. I'm sorry, but I haven't found another source for that composite material. I found it at an aircraft surplus store, bought every piece they had, and only have enough to complete my project with none to spare. Please let us know if you find another source.

    Subj: Compression
    Date: 3/19/03

    What is the maximum compression ratio you would recommend for these engines? I was planning on putting a '61 102 HP head aboard a '65 110 engine. Because of the 49 cc combustion space, the compression ratio would run just over 10:1. As the C/R increases, so does engine heat, stress and chances of detonation, right?? I could mill out a larger combustion space or build the shorter-stroke 145 cid engine instead. Any idea how much HP I could expect running an "early" with the OT-10 (with stock displacement)?? Thanks for any assistance you might give.

    John, josandt@netzero.com
    Reply from WW:
    There are a number of reasons why you would not want to build a 145cid motor. These are outlined in great detail in the 2002 Conversion Manual, available by credit card via PayPal at The Online Catalog, or by check or money order for $59USD (add $15 for international S&H, including Canada) payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802. The 164cid motors make much better powerplants. While 10:1 could be run on 100ll, I think it is a much better idea to stay closer to the 9:1 compression that is stock on 164cid powerplants. There is no real reason to consider putting early heads on a late motor. It requires machine work and late model heads are readily available.

    Subj: : Fine tuning
    Date: 3/18/03

    I now have 4 hours of run time on the Vair and just replaced the Ivo Prop with a 3-blade 54-inch Warp Drive prop. I set it at 50 pitch. It will run at 2400 rpm static at that pitch. So I need to tweek things to get it up to 2800rpm static. I havn't put a light on the timing yet, but have moved it around a little to see if there is a difference. I have yet to play with the advance, but it's presently set at 30 degrees at WOT. I have put in different needles in the Aerocarb. I can set it so that it's running very rich (engine starts to run rough and load up) to the lean side of average. And there's about 50 degrees difference in egt. Can't get the 100 degrees that Aerocarb recommends. My egt runs about 50 degress hotter on the left bank - adjust the runner length from the carb, maybe? The next thing that I will test is egt difference of each cylinder on one bank to see that my mixture distribution is equal. The engine runs smooth from idle to full throttle and has very good acceleration, so I'm thinking the cam timing is ok. My rear seal is leaking like a seive, so I'm thinking I may have put that seal in backwards. I put it in from the outside.

    Del Magsam, "Outlaw Sonex," New Richmond, Wisc., farmerdel@rocketmail.com
    Reply from WW:
    Again, congratulations on your running motor. The rear seal leaking is most likely caused by forgetting to put the oil slinger between the balancer and the distributor drive gear. It's a simple stamped steel disk, but it keeps oil from being thrown directly on the seal. Yes, the seal does go in from the outside, and the slinger must be put on before the rear cover goes on.
    30 degrees of timing advance will not ping unless you have very lean mixtures and high loads. I encourage everyone to use a timing light when doing their initial test runs. When you adjust your propeller for a higher static rpm, say 2,700-2,800, make sure that your timing stays within the limits specified in the Conversion Manual. The distributor may have a slight advance left to go at 2,500.

    Subj: BD4 as a 2 place w/ Corvair?--Thanks, I'll order Manual
    Date: 3/17/03

    Thanks, yes I've decided the Corvair makes economic sense regardless of which plane I decide on. I may go with the smaller KR2 or the CH60l Zodiac. Regardless, I will be ordering the Manual. Thanks again,

    Steve Mann, 601 or KR2, Rohnert Park, Calif., smann23@netzero.net
    Reply from WW:
    Thank you for your order. The Corvair is a versatile powerplant, and can successfully power many of the useful classic designs of homebuilding. The KR2 and the 601 are good examples of planes the engine is well matched to.

    Subj: 95 or 110 Heads?
    Date: 3/16/03

    With a Stromberg MA3 carburetor with the smaller venturi, would it be better to use the 95 or 110 hp heads?

    Alex Sloan, Greenbriar, Ala., alexms1@bellsouth.net
    Reply from WW:
    There is no effective difference in the heads once they are converted according to the Coonversion Manual, available at The Online Catalog Page. A lot of people worry that starting with a 95 will yield a less powerful motor when converted. This is not so. The 95 and the 110 have the exact same port and valve sizes. They have a slight compression difference, nothing significant. From the factory, the main differences were cams, timing and jetting. Since we change all of these things in the conversion process, either the 95 or 110 will yield an excellent conversion with perhaps as little as 2hp difference.

    Subj: Safety Shaft
    Date: 3/15/03

    I purchased a safety shaft from you recently along with an updated version of the Conversion Manual. My engine is going to have electric start and an alternator. My question is simple.... which end do I have the machine shop drill and tap the hole for the safety shaft? Please reply. Machine shop will be getting to my crankshaft and block in the next day or so. Thanks. Blue Skies, Always,

    Dave Long, 150pilot@suscom.net
    Reply from WW:
    The drawings in the Conversion Manual show that Corvair motors are always driven off the flywheel end of the engine. Thus, the safety shaft is threaded into the pilot bushing bore. VW motors are traditionally driven off the pulley end, but Corvair motors are always driven off the flywheel end.

    Subj: Corvair Salvage
    Date: 3/14/03

    I am very interested in your view that the country is over-run with Corvair cars and engines. I am somewhat reluctant to destroy a restorable car in a junkyard, as a collector will be deprived of just one more opportunity to do his/her thing after I leave. Nonetheless, I am scouring around, and in Greeley, Colorado, I have located two cars, and if I remember, they are both too early for my use. And the owner in Greeley wants $300 each for his. I located a place in Denver (south suburb) fairly near where I live, and several weeks ago the man there told me he had three of them, which he would sell for $150 each. While I don't consider three to be a whole lot, I thought I might be satisfied with that. However, when I went back to make a deal for the three, it turns out he only has one, a 1965 model, to sell at all. I recall you bought 12 or so for $1000, and I wanted to see a selection like that so I could really choose a nice one for myself. Frankly, I wanted to buy three books from you, so I could restore three (two for me and one for a friend) but now I am unable to do anything of the kind. I am not a happy camper. Can you provide any ideas on what I can expect in real life toward getting perhaps a newer 1968 or 1969 model? Am I wrong to think that a better choice? By the way, this guy does have a 1964 model but I don't know if that is acceptable.

    I called a junkyard right in Denver, and he was on his computer (I guess) and he said he could locate one in Oregon, and one in Michigan. Is THAT wonderful? $500 each. Plus shipping. These things don't sound plentiful at all. The guy that has one here for $150 claims that dealers are NOT hanging on to them as the age gets older. Off to the melting pot!! That is not going to help the availability or the price. I do not know WHAT to believe. Can you help?? Yours sincerely,
    Richard G. Alps, Littleton, Colo., Richardalps@aol.com
    Reply from WW:
    Your concerns are unfounded. First, the 1965 motor for $150 right under your nose would make a great conversion. The motors are not rare. Today in my hangar, a man dropped off and gave to me 2 1964 motors. These also would make good conversions. The details of this are covered in your Conversion Manual [available at The Online Catalog Page]. This man gave them to me because they were leftovers from a pile of motors he bought in North Carolina, from which two very nice conversions were built. This was a very nice gift, but it is also a good indication of how little the motors are really worth. Not in a million years will a stranger pull up in front of your hangar and give you two O-200 cores (value $8,000) for nothing.
    As explained in the Conversion Manual, forget looking at junkyards. The motors we want are in the hands of Corvair fans nationwide. There are at least five national Corvair junkyards owned by CORSA members that would gladly sell you an engine for half of what your local $500 ripoff artist wants. In fact, if he's shopping from Oregon, he is probably buying one for $250 from the Corvair Underground and doubling the price. If you really can't find one locally, you should just contact them directly.
    A number of people have had trouble finding an engine after looking for a week or two. But, stop looking in junkyards and contact CORSA and you'll have much more success. If there is not a local Chapter near you, go to the oldest auto parts store in your town (not a chain store) and ask the senior counterman if he could put you in touch with a Corvair person. Trace one or two of these leads, and you'll find plenty of motors.

    Subj: Engine Selection, Zodiac Motor Mount
    Date: 3/13/03

    Just ordered your Conversion Manual today and I have a couple questions for you. I found a 1964 engine locally that has been sitting in a dry shed for 30 years and apparently the rings must be stuck because you can't turn it over. Does the condition matter since it will be completely overhauled or should I look for a better one. Price is $125.00 including two older engines. I'm building a Zodiac CH601 HD and had intended to use the Jabiru 3300 until a friend reminded me about the Corvair. Reliability is the most important issue to me and from what I read and hear this engine has it along with the affordability.

    Another question is about an engine mount for my Zodiac: Where do I get one or would I have to make it myself? Appreciate your help. Thanks,
    Dick Schmidt, Zodiac CH601 HD, Menasha, Wisc., rschmidt8@new.rr.com
    Reply from WW:
    To my understanding, all the 601 series aircraft are the same from the firewall forward. I am looking into providing motor mounts and parts for these, the same way I already do for KRs and Dragonflys, etc. When the time comes, I will undoubtedly have at least motor mounts available for you. All of my other existing conversion parts are 100% applicable to 601s.
    $125 is a little steep for a motor which will not turn over. If you can talk him down to the $50-$75 range, it may be worth it. In many cases, I prefer to spend a little more money on a better core because they tend to be a little less work when overhauling.

    Subj: Case Studs
    Date: 3/12/03

    The top case studs are rusted off where the nuts are screwed over. What should I do about this?

    Dean Mitchell, Bay Village, Ohio
    Reply from WW:
    The top case studs on motors were exposed to water and grime thrown off the rear wheels of the cars. In states with salty roads, this tends to rust the ends of the studs. In extreme cases, the studs need to be replaced. Frequently, it is easier to find a perfect case than to replace the studs. Note that Larry's Corvairs in L.A. has a supply of excellent condition cases which they will UPS to you. Call them for details. If just the tops of the studs are shot, you can consider having a machine shop counter-bore the pads on the cylinder heads so that the nut will move closer to the centerline and have full engagement after you re-assemble the motor.

    Subj: Parts - Oil Pans
    Date: 3/11/03

    What is the status of your larger capacity oil pans? How far in advance do we need to order? Thanks,

    John Krumrine, Zodiac 601XL, College Park, Penn., jqk4@psu.edu
    Reply from WW:
    The first order of oil pans sold out very quickly. The new order is arriving this week, and I will have them on the shelf and in stock continuously from here on out. The popularity of the Corvair conversion now justifies me stocking all of the parts in my catalog for immediate shipment. Previously, there have been delays in shipment on some items, but this year, the growing acceptance of the motor justifies an even greater investment on my part.

    Subj: 1963 Corvair
    Date: 3/10/03

    Found a 1963 Corvair , the engine number is ti029zf. Is this an engine I can use? The car was an automatic transmission.

    Cary Howard, Monticello, Fla.
    Reply from WW:
    Every week I hear from people who have gone out and purchased Corvair motors from $100 to $900 because they wanted to get started before buying the Conversion Manual. Your money spent on a 1963 engine is unfortunately wasted. The Conversion Manual contains all the acceptable letter codes and head numbers, plus instructions for selecting a good core motor. I encourage anyone seriously contemplating the purchase of the motor to call if they have an immediate question. Arming yourself with the information contained in my Corvair Conversion Manual and studying it before throwing money at a core motor is the correct approach. Manuals are available in the U.S. for $59, payable by check or money order in US Dollars to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog Page (add $15 for international S&H, including Canada).

    Subj: Sun 'N Fun
    Date: 3/9/03

    I hope to make it to Sun-n-Fun in April . . . do you plan to be there? I have a few Corvair 164 engine parts to bring to ask questions about. Thanks for all your work in making an affordable flight engine possible.

    Gary Kaplan, Mt. Juliet, Tenn., gary@garyglenwood.com
    Reply from WW:
    Good to hear from you. We will be building engines all week at Corvair College during Sun 'N Fun, April 2-8, 2003, in Lakeland, Fla. Our full schedule is at the News From The Corvair Authority page. This is exactly the kind of participation we're looking for at this event. By all means, bring your Corvair parts (cleaned as outlined in the Conversion Manual) and learn with the rest of the group.

    Subj: Aerobatics
    Date: 3/8/03

    Having read some of R. S. Hoover's comments as linked from Ron Wanttaja's Web site about building an inexpensive airplane I got quite interested in something like a Piet, Corben or Fly Baby until I looked at the prices of (mostly runout) 4 cyl. Continentals (65-100 hp) in a year-old issue of Trade-a-Plane (ouch - runout or not they are NOT inexpensive!). Therefore I am quite fascinated about the idea of a Corvair engine for inexpensive flying.

    Now to my Subject; I do have an interest in Aerobatics. Would the Corvair be good for "Sunday afternoon aerobatics," say in something like a Baby Lakes or Starduster SA-900? (The literature Pete Bowers sent me on the Fly Baby even mentions its "excellent aerobatic ability".)
    Also, if I get infected by the speed bug, how would the Corvair do in, say, a 1 seat Midget Mustang or RV-3 (both originally designed for 90-100hp Continentals despite the subsequent horsepower races among homebuilders)? Sincerely,
    Mark Boberg, Oak Harbor, Wash.
    Reply from WW:
    You're quite correct in your assesment that the Corvair is an inexpensive alternative to the small Continentals. They are good engines, but the high price of parts for them means that most Continentals have been run on shoestring budgets for many, many years, and thorough overhauls on them are astronomically expensive.
    The Corvair has obviously flown a number of the original airframes you mention, like the Pietenpol and Corben Baby Ace. Numerous Corvair Conversion Manual owners are installing them in Junior Aces and Fly Babys.
    Everyone has a different definition of what "aerobatic" is. If you consult FAR Part 23, Pete Bowers and Curtis Pitts, you're going to get very different answers. You need to develop your own personal experience in aerobatics to judge your real interest. I have flown aerobatics in jets and 450hp Stearmans, and personally hard core aerobatics with negative maneuvers are not for me. I do feel that normal flight maneuvers and recovery from unusual attitudes should be in every pilot's skill set; if you have proper training, your Corvair-powered airplane can handle any of these maneuvers.
    The RV-3 was never designed to fly on 90 or 100hp. You can check the Van's Web site; I believe the minimum size listed is 150hp. On the other hand, Midget Mustangs do fly well on 85-100hp. I'm currently looking into a 3,100cc/Midget Mustang installation at our own airport. It looks like a very good match.

    Subj: Engine Parts at Sun 'N Fun
    Date: 3/7/03

    I intend driving down to Sun 'N Fun this year. I was hoping that I could pick up some engine parts while I'm there. Will you have available a 10/10 reground crank with safety shaft and studs? I can bring mine down with me as core exchange. I'm also interested in the prop hub, the light weight oil pan, and a remanufactured dual ignition distributor. Please let me know so that I can pack my distributor and crankshaft. Thanks,

    Neil Hulin, Zodiac 601XL, Cincinnati, Ohio, nhulin@hotmail.com
    Reply from WW:
    Good to hear from you. Let me take a moment to explain our crankshaft situation. We did a little less than 100 crankshafts last year on an exchange basis, but for various reasons only got about 40 good cores back. This temporarily depleted my on-hand supply of cranks. Currently, I am offering the same regrind and prep to drop in status that I always have, but it will be done to your own crank. The turnaround time, because the work is done at 2 different machine shops, is about 3 weeks. If you send us your crank now, we will be able to give it to you completely modified at Sun 'N Fun.
    All the other parts you mention I will have on hand at Sun 'N Fun. You can bring your distributor core with you. Distributor cores are not a problem, as virtually every one is rebuildable and I have approximately 200 cores on hand.
    Looking forward to seeing you at Sun 'N Fun. Our schedule is at flycorvair.com News from The Corvair Authority.

    Subj: Turbo
    Date: 3/6/03

    My recent review of your Web site indicates that you have completed a great amount of R&D since I last studied your development of the Corvair engine conversion for aircraft. I am very interested in your new motor mount and will be ready to order your prop hub and other components when I receive the New Manual and determine what other newer parts or assemblies you have available.

    You have listed the Christavia Mark I as one of the experimental aircraft that has been built with the Corvair engine. Turbo normalization is also of interest to me for maintaining power at mountain altitudes.
    Dick Schoen, Christavia Mark I, St. Paul, Minn.
    Reply from WW:
    I am very close to having a turboed direct drive motor that I believe will be the answer to the quest for more power while retaining the simplicity of direct drive. I have the engine in my shop now, and I have gone to great lengths to minimize any of the changes so the system can be of benefit to guys who already have built motors. I'll put the whole story in the summer issue of The Corvair Flyer newsletter.
    Thank you again for staying in touch. As you know, the work I've done has been a big part of my life, and while it's very popular these days, I will always remember the guys who recognized my efforts and supported me early on.

    Subj: Ring Gap
    Date: 3/5/03

    Today I started the reassemble of the engine with the able help of one of our EAA Chapter members. He is a licensed engine mechanic. We have the crank and camshaft installed and it checked well using the Plastigage. He requested I give you a ring and see what you suggested for the piston ring end gap clearance. He was looking at the Manual but thought that perhaps it should be a little more than the listed specs as the engine is being used for an aircraft. What are your thoughts on it? He showed me how to correctly increase the gap by filling the ends of the rings. Neat. Thanks for you help.

    Alex M. Sloan, Greenbriar, Ala., alexms1@bellsouth.net
    Reply from WW:
    You are quite correct in assuming that we like to run the ring end gap at the looser end of the range. When a cylinder is bored for a forged piston, and the rings are slid down in the bore to check, I like to see the ring gap closer to the upper end of the limit rather than the lower end of the limit. One of the great advantages of air cooled engines is that they can be run hot for several minutes. To do this without damaging the engine, the ring gaps cannot close, otherwise the cylinder wall will get scraped badly. Comparatively, a liquid cooled engine will boil off its coolant under the same circumstances. I have found almost all new ring sets to check out at the upper end of the limit, but it is a simple matter to insert the rings in the bore and check them with a feeler gauge to be sure.

    Subj: Flybaby
    Date: 3/4/03

    Starting a Flybaby project and wonder if the Corvair engine would be suitable?

    tkorange@localnet.com
    Reply from WW:
    Yes, it's a good match. There are even a number of guys working on two-seat Flybaby/Corvair projects. Although most Flybabys were flown on 65hp Continentals, its sturdy construction allows the use of more powerful Corvair motors. The Corvair's simple nature complements Peter Bowers' design philosophy with the Flybaby.

    Subj: Nice job
    Date: 3/3/03

    Hi, just a quick note. A friend here in Casper, Wyoming, is finishing a Pietenpol with Corvair power and has showed me your fine Manual, Corvair Flight Engines for Experimental Aircraft. For the past 13 years, I have owned and driven Corvairs; 5 are running, one turbo. I'm a Mechanical Engineering teacher, with some specialization more in diesel engines. Thought I would say congratulations on such a fine book and Web site. Your articles and book are so very well done and technically correct. You really have a thorough understanding of the subject and it is a treat to see things done so well. I wish you the best!

    Ardell Knudson, aknudson@caspercollege.edu
    Reply from WW:
    Thank you for the very nice compliments. Coming from someone who has both a background in the mechanical world and education, I take it as a real compliment. The work in the 2002 series Conversion Manual is not only the result of years of work on Corvair engines, but also the accumulation of a lifelong interest in things mechanical. Along the way I had many teachers, and I'm sure I never thanked them all properly, but a lot of the credit belongs to them. I'm sure many of your students feel the same way about you.

    Subj: Wag Aero Sport Trainer
    Date: 3/2/03

    William, I'm looking to build the Wag-Aero J-3 Cub with the shortened wing option (also the L-4 Observer conversion). Anyway, what do you think of the Corvair in this plane? Also, why not use the 140hp engine? I own a '63 110 Monza convertible and LOVE the engine. Thanks for your time.

    Rick Davitt, rickdavitt@shrinkpackaging.com
    Reply from WW:
    The Corvair is a good engine for either the standard J-3 or the shorter wing versions. A standard J-3's engine is of course only 65hp, and I have seen clipped wings fly well on motors as small as a C-75. Although both of these engines make their rated power at low rpm, the difference in thrust per horsepower is not nearly what most armchair theorists would have you believe. The Continentals turned 72" diameter props. The Corvair can easily turn a 68" or 70" prop, and the additional horsepower of the Corvair makes for an engine installation with substantially more thrust than the small Continentals. If anybody tells you differently, simply ask them which Corvair motor they tested. I have found that the people who blindly repeat theory have never tested anything.
    The whole story on 140s is covered in the Conversion Manual, available by check or money order for $59USD (add $15 for overseas S&H) payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802. You can pay by credit card via PayPal at the Online Catalog. But in a nutshell, the 95 or 110 motor converted according to my Manual actually makes more power below 3200rpm. Since all of the operation of a direct drive motor in an airframe like an L-4 is below this rpm, it is the optimum motor. Additionally, the 140 is the only motor in the Corvair line known to drop valve seats. For these reasons, I recommend the 95 and the 110.

    Subj: Corvair College
    Date: 3/1/03

    I'm going to try to make it to your place prior to Sun 'N Fun, and also to SNF. What will I need besides long block? Do you have any TRW pistons? Will you have any prop hubs available? I'm planning on using front mounted starter and alternator accessories. I already have Corvair fuel pump and 12 plate oil cooler.

    Greg Jannakos, Zenair 601, Ga., gpjann@juno.com
    Reply from WW:
    The next step on your engine would be the connecting rods, pistons, rings and cylinders. Your Conversion Manual details exactly which parts these are, and what needs to be done to them. I generally do not keep a big stock of pistons and cylinders and similar items on the shelf because they are readily available from the sources listed in the Conversion Manual, and I avoid being the middleman on standard parts. Once you have these items on hand, the next step would be to bolt on the cylinder heads, which of course need a valve job before they're installed. Cleaning and painting the pushrod tubes and the rest of the valve train components before hand makes the assembly go smoother. If we have to take time to do these in my shop, it reduces what can be accomplished in a weekend. My pre Sun 'N Fun Open House is the weekend of March 15-16. All of the conversion parts that I sell, like prop hubs, aluminum oil pans, hybrid studs, etc., will be available.
    Our Sun 'N Fun schedule is posted at News from the Corvair Authority. All Conversion Manual owners are invited to build up their engines for free at Corvair College, just as we've done at the past three Colleges. Everyone is always welcome to watch and learn. The only difference is that this year's College is at Sun 'N Fun rather than at my hangar, and they charge admission. Their Web site is www.sun-n-fun.org. Looking forward to seeing you in Lakeland.

    Subj: High compression Corvair
    Date: 2/28/03

    I just ordered your book on Corvair conversion, but I have a question I am sure is not covered in it. I will be building a 194 cid engine and I would like to use as much as 12:1 compression on it. I will not do this to gain horsepower, but rather to retain the 75% hp to a higher altitude. I would also want the additional compression down the line when I convert it to use alcohol fuel. My question to you is, would this be possible without hurting the reliability very much? If you do not know the answer, could you put me in touch with someone that can answer it? By the way, I will be putting it in the lightest weight BD-4 ever built. Thank you for your time.

    Dale Neddeau, BD-4, dneddeau@hotmail.com
    Reply from WW:
    Your question is certainly not run of the mill, but it is far from the most unusual one I've ever received. I do not believe that raising the compression ratio will retain as much power as you think at altitude. The motor would also detonate if the slightest mistake was made about opening the throttle too far at low altitude. A naturally aspirated motor loses power at altitude because the same volume of air has fewer molecules in it and because the effective cylinder pressure is dropping. Your proposal would counter the second factor, but not address the first. I would honestly suggest considering a turbo instead. I am continuing my work on direct drive 2,700cc turbos, and I think it would be a much more promising altitude engine.
    As for running the motor on alcohol, most of the high end Corvair powered sand dragsters run on alcohol. Guys like Bob Sutcliffe, whose number is in the Manual, have a fair amount of experience with this. My personal experience with alcohol is limited to motorcycle drag racing. The horsepower improvement potential is about 15% on a naturally aspirated engine. Against this, peak power air/fuel mixture is only 6:1, giving the engine a ravenous appetite for fuel. And the main problem: it's horribly corrosive and will attack almost everything in a standard fuel system, including the tank, the lines, the inside of the engine.
    A 2,700cc turbo Corvair motor would probably be a much better bet for your ultra light weight BD-4. (Note: BD-4s are not normally within the Corvair's hp range.)

    Subj: TITAN AIRCRAFT'S NEW T-51 3/4 SCALE ALL-METAL MUSTANG
    Date: 2/27/03

    Hi William, always enjoy your articles on what's going on in the aviation/Corvair engine world! I shared a few e-mails with you last year regarding the Corvair engine's ignition system, and about the old '66 Dodge pickup and engine with 86,000 original miles I found and bought. I have overhauled several engines myself over the years and served as a crew chief/mechanic on Hueys in Vietnam and Germany. Always enjoy engine work and do most engine and other repairs on vehicles I own.

    Now I am truly interested in buying a kit airplane to use a Corvair engine in. Last year I was interested in the Loehle wood and fabric P-51 Mustang replica, but when I mentioned using the Corvair engine with their P-5151 model, Sandy Loehle told me they had not heard of it, so never considered it. When I told her the weight of the engine, she thought that the weight may be too much for their design. They had no plans for attempting any tests, but now with subject Titan aircraft coming out, they may become more "adaptable" to compete.
    Do you have any information on subject aircraft's potential for using the Corvair engine? The Titan T-51 is gorgeous looking in the pics I have seen, and since the P-51 was always my fav WWII airplane, I would be thrilled to build and fly one! Here is the Web site for the Titan: http://www.titanaircraft.com
    Thanks for any help you can provide, although it appears you have very limited time, so I feel fortunate if I hear from you. Sincerely,
    Wendell McGinness, Titan T-51, Gig Harbor, Wash.
    Reply from WW:
    We saw this plane in person at its Sun 'N Fun debut last year. It drew a huge crowd. The pictures don't do it justice. It's very nice. I believe the intended engine for it is a 912S or a 914. They are working very hard to keep a decent useful load and stay under 1,232 pounds for the new Sport Pilot rule. If you're really interested in this plane, you might want to call them and ask if it could be flown on an O-200. If the answer is yes, it's a good possibility the plane could be Corvair powered.
    I have recently been contacted by a company in Australia building a 1.6:1 gearbox for the Corvair. More information is due in the coming weeks, but this aircraft might use such a setup to turn a more scale prop. I almost never suggest using a gearbox, and this one is as yet unproven. But, I'll keep an eye on it for everybody.

    Subj: Corvair in Ercoupe?
    Date: 2/26/03

    Would the Corvair be a good engine for the 415C Ercoupe?

    jleonard@cox-internet.com
    Reply from WW:
    Most Ercoupes were powered by 75 and 85hp Continentals. The Corvair, at 100hp, could certainly power the aircraft. All of the difficulty of mating the two would be in getting approval from your regional FAA office, and operating the aircraft under the restrictions they might impose. If you're considering such a project, contact your local FSDO on the approval procedure and flight limitations.

    Subj: Dual ignition
    Date: 2/25/03

    Do you have a dual ignition set up for the Corvair and possibly dual plugs? I have had to put a plane down in the water due to ignition problems, so I hope you understand the reason for my question. Thank you.

    Paul Mallard, papaquack@aol.com
    Reply from WW:
    The Conversion Manual details all the developmental work and experience I have with dual ignition. My current dual ignition setup has two of all the heat sensitive components: points, coils, etc. Yet it retains the simplicity of single plugs. It is flight proven with hundreds of hours of service. I sell these distributors, complete, including Priority Insured shipping, for $219 at the Online Catalog, or you can send a check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802.

    Subj: Change to Manual info
    Date: 2/24/03

    I think the phone company changed the area code on you...Page 21 shows CORSA phone number as 709- and it is now 630....you might want to change that...

    Bob, rwbtoy@internetcds.com
    Reply from WW:
    Thanks for the tip. For everyone else reading this, CORSA is the Corvair Society of America. It is the national group for owners' of Corvairs. It is a large group, with state and local Chapters.

    Subj: C-150s and Corvairs
    Date: 2/23/03

    I'm looking at a couple of Cessna 150 airframes, less engines. They can be had for next to nothing. Is this a candidate for a Corvair engine, and if so am I opening a can of worms? Looking forward to hearing from you.

    Ron Jones, Shelby Twp., MI
    Reply from WW:
    A Corvair would certainly power an early model Cessna 150 nicely. The earlier model 150, the better; they were lighter and had lower drag. Here's the catch: You'll have to receive special permission from the FAA after filing proper documentation, and there will be restrictions on how and where you can operate the aircraft. The documentation may have to include a report from a licensed engineer on such items as engine mount design, etc. It can be done, but I highly suggest you contact your regional FAA office and learn all the details before you actually acquire the aircraft.

    Subj: How to clean the block?
    Date: 2/22/03

    What is the best procedure to clean the block? If sandblasting, what media do you use? If some cleaning fluid, what is used? Or other???

    Thanks, Greg, g_geer@blomand.net
    Reply from WW:
    The 2002 Conversion Manual contains an extensive section on cleaning techniques. In short, never sandblast anything on the motor. This restriction includes glass beading. The only acceptable blast media would be Walnut shells or plastic. Glass or sand will upraise and destroy the fit under the bearing shells, in the lifter bores and on the mating surfaces. Gunk engine cleaner, pressure washing and carb cleaner and brushes are a much better way to clean the aluminum parts on your Corvair motor.

    Subj: Just Starting
    Date: 2/21/03

    Hi to you William. My name is Charles Storey and I'm just starting to consider building because the cost of buying aircraft has gone into orbit and just doesn`t seem to fit my wallet. I've been talking to people about building and the subject of engines came up and I was told that your Corvair engine is going to be the recommended engine for this. Now I've said all that to say this: I'm no Mechanic. I'm good at carpentry, and just about all home repairs, and can change a plug or two. I can take one part off and put another one on, so is this going to be too big of a job for someone like me to tackle, or should I just hope to find one already done. Stuff like this really confuses me. Any thoughts or suggestions will be most helpful, because as you know, money doesn't grow on trees. Thanks for your time. Hope you can help.

    Charlie Storey, RAMBLER444@aol.com
    Reply from WW:
    Many years ago when I started my work with Corvair motors, it was with the sole intention of helping out guys just like you. A big part of the reason I chose the simplicity of direct drive, air cooled and simple systems is because it's the only practical engine to teach people to build for themselves. Complex engines would be beyond the scope of safely teaching first-timers to build for themselves. By and large, a Corvair motor, as converted, requires no machine work for you to do. It requires only careful assembly and light fabrication. When a first time builder expresses the same concerns you have, I'm never worried. In my experience, first time guys exercise more care and tend to build by the book rather than with a been there, done that mentality. Converting the Corvair motor is much easier than building the simplest airframe.
    Occasionally people ask about buying a motor that's "rebuilt." I sincerely recommend against this. In the past years, with my help, dozens and dozens of Corvair motors have been rebuilt. The owners are justifiably proud and I cannot think of a single one which is for sale. Occasionally, stories surface of engines for sale, but I know from our records that we've never met the seller, and he doesn't own a copy of the Conversion Manual, so I largely suspect it's just an overpriced car engine. You're always much better off to buy a good core motor and rebuild it yourself. You'll know a lot more about the motor when it's done, you'll have the pride of having created it, and you'll be putting your trust where it belongs, in your own craftsmanship.

    Subj: Corvair College #4
    Date: 2/20/03

    I had a request for more info on the upcomimg Corvair College. What is the cost & exact dates/time (since Sun 'N Fun is running Wensday through Tuesday).

    Michael Amick, mkamick@edge.net
    Reply from WW:
    Our Sun 'N Fun schedule is posted at News from the Corvair Authority. All Conversion Manual owners are invited to build up their engines for free at Corvair College, just as we've done at the past three Colleges. Everyone is always welcome to watch and learn. The only difference is that this year's College is at Sun 'N Fun rather than at my hangar, and they charge admission. Their Web site is www.sun-n-fun.org. Looking forward to seeing you in Lakeland.

    Subj: Corvair for Australian Piet
    Date: 2/19/03

    G'day, have just started on a Piet long fuse, (plans from Andrew P) and would like to use a Corvair. As you are probaly aware they are a bit thin on the ground over here so would like to know whether you have looked at shipping a suitable core and some of your other mods to Oz. I have noticed on one of the UK sites that you have sent some there. If you can let me know if it can be done and an estimate of shipping costs I will start talking to customs at this end to see where I stand.

    Regards, Arthur Johnson, Townsville, Australia, aejonhson@email.com
    Reply from WW:
    It is true I've shipped aircraft motors and cores to Brisbane and Birmingham. Incidentally, I've shipped Manuals to such far flung places as St. Helena, Sai Pan and South Africa. The last time we sent a motor to Australia, the shipping was about $500 by air freight. Contact me when you're ready.

    Subj: CORSA motor
    Date: 2/18/03

    Thanks for returning my e-mail, and the info about the prop. I was a little alarmed to hear about the potential destructive flaws with this motor. I hope you can enlighten me some more to what they might be. The motor I have is a genuine Corsa motor. Serial number TI 216 RB. Mileage - 63,000. It was overhauled according to the 1965 Corvair shop manual. I purchased it from an ex- helicopter inspector in England, now in Adelaide, Australia, who originally rebuilt it in England and brought it out to Australia some years ago. It is the 4 carburetor engine, which was converted to a single Aircraft Carby underneath, which I have now changed to a Dual side draught Webber, one half of the 45mm carby feeding each side of 3 cylinders, also underneath (I will not be flying over 5000 feet). It has not been run since re-built. However following is what has been done to the motor internals:- Crank crack tested using X-Ray. Crank dimensionally checked. Cylinder head cooling fins cleared of casting flash. Airways opened up. Cast iron valve guides replaced with aluminium bronze guides. Valve seats re-cut and valves re-ground and assembled with new springs. GM cast alloy pistons replaced with TRW forged alloy pistons. Double capacity oil pump fitted. Camshaft replaced with Otto TB-10 shaft to improve lower RPM performance. New hydraulic tappets. Sump replaced with cast aluminium ribbed cover. GM main & big end bearings replaced with TRW CL-77 High performance shell bearings. All oil seals replaced and push rod "O" rings replaced with Viton rubber seals. Engine re-assembled with shake proof bolts and hardened flange cylinder hold down nuts. Crankshaft, Prop Hub, Harmonic Balancer and starter ring dynamically balanced. Pistons and con rods Statically balanced. Also Thrust Bearing:- Based on American experience (Bernie Pietenpol), It is of the later type with a thrust face on both halves. All parts replaced are either TRW or OTTO parts. Is this sufficient not to have to strip the motor down again, or are the potential problems not covered by what has been done. Please let me know what is needed to be done, and what your Manual is now worth. Also do you accept VISA Card. Hoping to hear from you again.

    Regards, Roger Foster, randgfoster@hotmail.com
    Reply from WW:
    Thank you for your detailed records. It sounds like the engine had a first class rebuild. The only item on the engine that I would change would be the cylinder heads. Although this sounds extensive, it's not. Virtually all the other parts on the motor will bolt right to them. The only difference is that the 110s require a slightly different rocker arm. Your cylinder heads, as they are, are worth about $400USD. You could easily find someone with whom to exchange them for a fully rebuilt set of 110s or 95 heads. The 140 heads do not make power at direct drive rpms. This is covered in the Manual, which costs $59, plus $15 for overseas S&H. You can pay by credit card via PayPal at the Online Catalog. Although several people are interested in Webers, the best setup is yet to be determined with this carb. I strongly suggest running both barrels into a common plenum. A single barrel feeding a long intake track on the Corvair can send a resonant pulse down the tube. This is eliminated by feeding a common plenum. It's not a problem on the car because the intake is short.

    Subj: Excavating an Engine
    Date: 2/17/03

    Hi, Thanks for the manual and video tape at San Geronimo, TX.

    I have the 1965 Corvair shop manual and after reading the engine and transaxel removal instructions and special tools needed, I am still wondering what to do at the junk yard when I go to pull the engine myself. What process do you recommend for the "Pull the engine from a car sunken into 20 years of dirt"?

    O.K. Then how much would the shipping be on one of your engines to San Antonio?

    Richard Elder, San Antonio, Texas, relder@flash.net
    Reply from WW:
    We had a great time in San Antonio. The best way to remove the motor from a late model car is to jack up the back end of the car till the bumper is 30" high or so. Remove the bolts around the bell housing, with the exception of the bottom two, and disconnect the motor from the rest of chassis, wiring, fuel line, etc. With the carburetors removed, you can lower the car down, disconnect the rear motor mount by the harmonic balancer, and take the bottom two bolts out. When you jack the body up this time, the motor will sag down and it can be slid away from the transaxel and out from under the car. If the car has an automatic transmission, you'll have to disconnect the three bolts from the torque converter to free it from the flex plate. Richard Finch's How to Keep Your Corvair Alive has step by step instructions on his method of engine removal.
    I have traditionally sold dozens of engines inspected and guaranteed to be rebuildable for $299. This served me well to jumpstart the re-emergence of the Corvair motor, and got a lot of people going. Today, the popularity of the motor leaves me little time for tasks that guys can easily accomplish in the field, such as acquiring a core motor. The popularity of the motor dictates that I spend more time doing things like driving to Texas to teach you and other builders. I heartily encourage you to get your core motor locally. Not only will it be cheaper than me having to ship it to you, your tracking it down and liberating it from a junkyard will provide a much more dramatic beginning to the story of how you built your own airplane motor.

    Subj: Carb Ice
    Date: 2/16/03

    Does the Conversion Manual deal with adding fuel injection? I'm paranoid when it comes to carb ice.

    Ron Mills, Burbank, Calif., MILLS42@aol.com
    Reply from WW:
    The Conversion Manual covers the issues surrounding fuel injection, and my opinion that carburetors are a much better idea for amateur aircraft builders. Plenty of airplanes have automatic carburetor heat; an Ercoupe is a good example. There is no need to be paranoid about carb ice. If you read the Web site closely, on the Carb Ice Page you'll learn that fuel injected engines are not immune to carburetor ice. The complexity of installation and high pressure fuel pumps associated with fuel injection are things of which to be leery. People have flown millions of hours on carburetors, even without automatic carb heat. This has been done safely. Amateur fuel injection does not have a safety record to match this.

    Subj: Looking for Engines in Indiana
    Date: 2/15/03

    William, I just ordered your Conversion Manual a couple days ago using your PayPal method [Online Catalog]. My wife told me to just order it by mail, but I want it yesterday.I wanted to know if you know of any places in the Indiana area that may have an engine or two laying around? If they are what I need to get the job done, I will travel to Illinois or Ohio. Thanks in advance and I'm looking forward to getting your book. I'm hoping to put it in a KR2S some day. Thanks again.

    Bob Glidden, KR2S, Martinsville, Ind., glidden@ccrtc.com
    Reply from WW:
    Thank you for your order. I'll research my records and also invite anyone who reads your request here to contact you directly with any leads in your area.

    Subj: Engine break-in runs
    Date: 2/14/03

    Hi William. I have two hours of run time so far, 4 half hour sessions. On the last run, I did 30 seconds of WOT at three different pitch settings. The Ivo Prop range is 30 to 90. With it set right in the middle (approx 60) the rpm was 2300. I turned the prop back 1 turn (approx 54), I got 2400 rpm. And then I turned it back another turn (approx 48) and got 2500 rpms. Is the Ivoprop so far off that I don't know what pitch it is at, or does that static rpm sound right for a 60 inch prop. I have the carb set pretty decent. I haven't put a timing light on it yet. How many hours should I run it before I do extended WOT sessions. And how long should I do WOT at a time. And what static rpms should I try to achieve with a 54 inch wood prop.

    Del Magsam, "Outlaw Sonex," New Richmond, Wisc., farmerdel@rocketmail.com
    Reply from WW:
    Good to hear from you. First, before anything else, verify your maximum timing advance. For ground runs and break in, use 30 degrees of total ignition advance as an upper limit. You'd like all this advance to be in before 2,400 or 2,500rpm.
    The propeller pitch sounds like it's in the right neighborhood. As you know, I'm no fan of Ivoprops. Keep a very close eye on the hub for any signs of separation or rough running behavior. The Ivoprop I sold to Bob Bean for his Lycoming-powered Tailwind disintegrated in the 1999 Sun 100 Air Race. If you choose to fly this prop, please pay very close attention to it.
    You want your static rpm to be approximately 3/4 or more of your planned WOT level flight rpm. I would not use less than 2,500rpm static in a plane like a Pietenpol, and with a smaller diameter prop in the 54-58" range, I'd shoot for a number like 2,750 or better. Before any runs at all, make sure that your engine is completely baffled, and you run it with the cowling on. Before I fly a motor, I like to see a 30-45 second run with the airplane blocked up to its maximum angle it will see on climb out to verify that fuel flow at full power is adequate. Keep an eye on the oil pressure gauge also. With all of your baffling and cowling in place, and the engine properly broken in and warmed up, you can run the engine at full throttle as long as the cylinder head temperature is in the green arc. Before the engine is fully broken in, I would limit WOT to about 2 minutes.

    Subj: Crankshaft dampeners
    Date: 2/13/03

    Are crankshaft dampeners used on the Covair engine? What brand do you use and do you sell them? Thanks,

    Howard, howash@juno.com
    Reply from WW:
    Almost all 164cid Corvair motors left the factory with harmonic balancers. The standard harmonic balancer will fit any model engine I recommend for flight conversion. Most of these balancers have damage to the rubber after 35 years. Dale Manufacturing has rebuilt thousands of balancers, replacing the rubber with cast urethane. These balancers are available from the suppliers listed in my Conversion Manual. They are not expensive, and I have used one on every motor I have ever built.

    Subj: Reverse rotation 'Vair
    Date: 2/12/03

    In your Conversion Manual you mention that you are working on a reverse rotation Corvair engine. I'm currently kicking around the idea of a twin BearHawk and was wondering what luck you've been having and how far along in the process you are.

    Dr. Andrew Rekow, BearHawk, Waterloo, Iowa
    Reply from WW:
    I am building the reverse rotation motor currently in the shop. I expect it to be done just after Sun 'N Fun, and I'll have a complete list of the details that go into it in the Spring issue of The Corvair Flyer newsletter.

    Subj: Christavia MK IV
    Date: 2/11/03

    Would the 4 place Christavia MK IV be severely underpowered with the Corvair motor? Thanks for any info.

    Joe, antjuju58@yahoo.com
    Reply from WW:
    I am not familiar with the Christavia MK IV performance details. I did note that the Christavia 2-seater was originally advertised to fly on 65hp, but the general consensus of builders was that 90 or 100hp was a practical minimum. This leads me to believe that the four-seater would require more power than the Corvair could economically deliver.

    Subj: Just started
    Date: 2/10/03

    I just started tearing down my engine, and I have a few questions. I bought the engine from the Corvair Ranch in Gettysburg. It is out of a '66 and has the RD Towanda suffix.

    When I removed the first head, I saw that the one piston had a hole burnt through it. I'm planning on replacing all the pistons and rods, so my question is, would this type of damage have created any other problems with this engine that I should be looking for? The engine turned over, but could it have bent the crank? Thanks,
    John A. Krumrine, Zodiac 601XL, State College, Penn., jqk4@psu.edu
    Reply from WW:
    It is not likely that the motor was damaged at all by having the weak, stock, cast piston let go. I would be particularly careful when cleaning out the oil cooler and the oil galleries, as this metal went somewhere in the motor. The people who rebuild your connecting rods will be able to check the straightness of the rods. A standard rebuild as I recommend in the Conversion Manual (available by money order or personal check for $59USD plus $15USD for S&H for those outside the U.S. payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Product Catalog Page) will work fine on this motor.

    Subj: Sonic Detectors
    Date: 2/9/03

    On Page 17 of your 2002 Manual you refer to a "stand-alone sonic detector" in a back issue of Contact! magazine. Doing word searches on their Web site on their back issue summaries turned up nothing using the word "sonic" or the word "detector." However, using the work "knock" turned up:

    Issue 28: "Steve Parkman develops a stand alone engine knock sensor. Complete DIY plans are included."
    Q1. Is that the issue to which you were referring?
    Q2. Also, what oil temp min and max limits would you suggest for Take-off, Climb and Cruise? Thanks,
    G. Andris Vaskis, Manual #5236, vaskis@gte.net
    Reply from WW:
    Yes, that is the Contact! issue to which I'm referring. Pat Panzera, panzera@experimental-aviation.com, who is the current editor of Contact!, is a Corvair engine builder. Also, Steve Makish, Boca Raton, Fla., is flying his Corvair-powered KR2 with an MSD knock detector. These are available from hot rod shops.
    I would consider 160F to be the lowest oil temp I would fly at; 180F would be a better idea. Ideally the motor would operate above 212F to boil off any condensation or entrained water in the crank case. New motors will occassionally hit 260F on a climb. After a few hours of operation, you'll notice the oil temperature will drop 20-30 degrees due to reduced internal friction in the motor. We run fully broken in motors on synthetic oil. I don't have specific information on what is too high for synthetic oil, but I strongly suspect you could run it 30-40 degrees hotter than non-synthetic oil without damage.

    Subj: John Deere Alternator
    Date: 2/8/03

    William, we have the new John Deere Alternator that you recommend in the Manual but have run into a problem in mounting it so it can be driven. Our question is, "If we drive it from the original balancer pulley it will be turning in excess of 8,000 RPM,-- Will it stay together or will it tend to throw the segments out of the armature?" We have clearance to add a smaller pulley to the face of the balancer but the mounting would be more difficult so we would like to drive from the balancer pulley. Please advise us as to what you recommend? We are anxious to get this engine running so we can be ready for the fly in season. Respectfully,

    Ray and Rich Hill, Pietenpol, raydot@pcpartner.net
    Reply from WW:
    We have an awful lot of flight time driving the John Deere alternator from the stock pulley, so I can assure you that it works, even though the rpm is high. The design of the unit is such that only the magnets are rotating, and they are bonded to the inside of the cup-shaped outer housing. Thus, centrifugal force holds them in place instead of straining the bonds. I have momentarily turned one of these 16,000rpm by accident, and it did the unit no harm. Reducing the pulley diameter is technically a good idea, but not necessary.

    Subj: CH701
    Date: 2/7/03

    Will this engine work in a ch701 or is it too heavy? Thanks,

    Miles, M150@aol.com
    Reply from WW:
    The Heintz family has told me directly that they do not want engines which weigh 200lbs. or more in the 701. Despite the fact that their 701 brochures have pictures of engines like O-200s and EA-81s, which weigh as much or more than a Corvair, they do not encourage installations like this. A number of people who liked the 701, but wanted to use a Corvair, are now working on an aircraft called a Pegzair from Canada. You can find out more about it in the EAA Aerocrafter catalog.

    Subj: Forged Pistons
    Date: 2/6/03

    Mr. Wynne, Turns out Larry @ Larry's Corvair is recommending boring out a '60 cylinder (not a '61 cylinder) to the 110 HP standard piston size. Then fasten it to a late model case and crank. Top it with a '61 102 HP head (9:0 compression). Run standard size 110 forged pistons on a late model crank. It seems to me that the boring process increases the volume of air being compressed - therefore, the CR must increase. Larry says no, it doesn't. He insists that he's done this same operation for other aircraft builders. Can you help here? Also, do you know if the '60 heads are heavier? Too heavy? Would appreciate any help you might care to give. Thanks.

    John, josandt@netzero.net
    Reply from WW:
    The operation as Larry described will work. The Corvair's advertised compression ratios are slightly optimistic. I haven't done the calculation, but would suspect Larry is correct that the compression ratio is just a little over 9:1. '60 cylinders are slightly heavier than others, but it's not much, maybe 2 pounds for the whole motor. The '61 heads should weigh just about the same.

    Subj: I'm inspired now... hand me the wrench!
    Date: 2/5/03

    Thanks again for visiting our EAA meeting last night. It was definitely an exciting presentation and I am now pretty certain that I will be embarking on a Corvair project this year... as soon as I get through the wedding I'll be getting your Manual and looking for an engine core. (Maybe sooner if I can manage it!) I've realized that working on these engines is not nearly as scary as I had come to believe previously. Looking at a typical modern car engine can be a bit imposing, but when you see the Corvair motor, you realize that there really isn't that much to it. The thought of building an engine for a homebuilt has gone from being something that I was going to leave to the experts into something that I both can and want to achieve myself, with the expert's friendly guidance and the benefit of experience gained by those who have done it before me. Like you said, learning by doing instead of merely buying the engine will help me gain knowledge and skills that will make me a better airplane builder and a safer pilot. As far as I can tell, it would be hard to beat a Corvair for a good engine to learn these skills on... it's not all that complicated! You guys have a great attitude that truly reflects the spirit of sport aviation that has attracted me to experimental aircraft for longer than I can remember. I will definitely see you guys at Sun 'N Fun to learn even more.

    Will forward a copy of the EAA meeting report when I'm done. Thanks again to you, Gus, Arnold, and Dave... everyone enjoyed it a lot and were genuinely excited about Corvairs!
    Mike Whaley, merlin@ov-10bronco.net, MerlinFAC@cfl.rr.com, Webmaster, OV-10 Bronco Association
    Reply from WW:
    Thank you for your kind words. We got your newsletter and it looked great. We look forward to seeing you again at Sun 'N Fun.

    Subj: Corvair engine for Zodiac XL
    Date: 2/4/03

    Just thought I'd drop you a quick note to say that I'm building a Zenith Zodiac 601XL, and I've been following with some interest the recent indications that you may be working with a Zenith builder to create a FWF package for the XL. If there is any truth to that, I just wanted to add myself to the list of interested builders. The Corvair conversion seems to be just the ticket for an economical powerplant for my XL (and yes, I already have a copy of your Manual!). Any word on when you might realistically have a FWF package available, if that is still your intention? Thanks.

    Mike Fortunato, Zodiac 601XL, mike@city-commercial.com
    Reply from WW:
    I am still working toward that package. Please note that I'm working on it independently, not with the factory. The Heintz family remains neutral on alternative engine installations which they have not personally tested. While they have been fairly supportive, the development of the combination is being done solely by me here. I'm very busy prepping for Corvair College #4 and Sun 'N Fun, but I suspect I could have this done by Oshkosh.

    Subj: Bell Housing
    Date: 2/3/03

    William, Thank you for taking time out of your schedule to reply. Actually after I sent the e-mail to you, a fellow called who had a Corvair about 25 minutes from the house. The motor turned over so I offered him $100 for it. He accepted, then ended up giving me the whole car. It was the RF designation and had matching heads of the 110 non smog variety. Haven't taken it apart, but everything looks ok. Since I made a deal with the guy in Little Rock, I feel obligated and will make the drive. I shouldn't have been so hasty, but he has my word. Lastly, will the bell housing for the standard transmission work, or will I have to obtain one from an automatic? Best Regards,

    Ed Jones, Xocouple2001@aol.com
    Reply from WW:
    We're answering this on the laptop while driving down the road. Gus is in the back seat and says thanks again for dinner in San Antonio. On the bell housings, either one can be used. They're completely interchangable. Keep in touch. We'll see you soon.

    Subj: Engine Choices
    Date: 2/2/03

    When you have a wide choice of Corvair engines, is there a particular one you would prefer? Also, they will sell me an untested engine for $350 and a running engine for $450. Is there any advantage to buying the running engine if I plan to rebuild it anyway?

    One final question. I have a Subaru Legacy wagon and hope to pick up the engine in my car. I know about all the measurements, but do you know of anyone who has ever tried to transport a Corvair engine in this size vehicle?
    Thanks for your help. I 'm hoping I'll be able to get to Sun 'N Fun and meet you personally.
    John A. Krumrine, Zodiac 601XL, State College, Penn., jqk4@psu.edu
    Reply from WW:
    The Corvair, stripped of the outer sheet metal, will certainly fit in anything pretending to be a station wagon. In looking for a motor, generally we're looking for a 1965-69 95hp or 110hp. All the letter codes and serial numbers are contained in great detail in the Conversion Manual, available by money order or personal check for $59USD (add $15 for S&H outside the U.S.) payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog. Please note that either motor, the 95 or 110, will produce the same 100hp when converted for aircraft use. It does not matter which one you start with. For $450, the motor would have to run pretty darn well. This includes idling well and not smoking. Running motors have the advantage that they are almost always rebuildable at a lower cost. The price these people ask demands the motor be in very good condition.

    Subj: Corvair Prop
    Date: 2/1/03

    I have obtained a Corvair Corsa motor which has already been modified for Aircraft use, with an output of approximately 100 hp, but I am currently remodeling it to suit my requirements. It will be going on a cantilever low winged single seat aircraft. What I would like to know is, what type of ground adjustable propeller do you recommend, and what diameter. The engine will have a maximum rpm of 3300 revs. I need a ground adjustable prop, as at this stage, I do not know what pitch I will need and I will have to experiment. Can you assist me please. Hoping to hear from you.

    Roger Foster, randgfoster@hotmail.com
    Reply from WW:
    I will be glad to help you in any way I can to ensure you safely operate your motor. Anything I comment on comes from first hand testing. The Internet being what it is, a lot of advice is tossed around by people who have never tested anything.
    Corsa refers to a 1965-66 140 or 180hp Corvair motor. I have flown both of these motors in the direct drive form and they perform poorly. Additionally, they each have potentially destructive flaws which are not shared by the vast majority of non-Corsa Corvair motors. A lot of people use the term Corsa loosely, so perhaps you do not have one of these engines, but it is a serious matter, so I ask.
    Before you fly a motor, you need to know what is inside. Despite the fact that I have sold thousands of conversion manuals, many people do not follow recommendations I make. It is a free world and this is OK, but many of these motor are later sold as "converted according to WW's manual" when they are not really close. A lot of this is small but crucial deviations which can be corrected without too much work. It is well worth checking into what you have. As for props, there is only one adjustable one which is flight proven on the Corvair, the Warp Drive. I would start with a 66" two blade without tapered tips. This can be trimmed if it proves to need it. We have sold a lot of these, they cost about $600. They work very well. Write back with any question you may have. I highly suggest a copy of my Conversion Manual, available by money order or personal check for $59USD (add $15 for S&H outside the U.S.) payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at our Online Catalog Page.

    Subj: Corvair College Curriculum
    Date: 1/31/03

    Thanks for the new info. I have a question about bringing a motor to Corvair College. Do we break them down, clean them, and rebuild them there? Or do you start by taking motors that have already been broken down and cleaned? If the latter, then I would just need to buy a rebuild kit from say Clark's Corvair and bring a good clean motor? Just wondering what all specific tasks are performed at the event. If you could send me a list of what all is covered, I would appreciate it. Thanks.

    Greg, g_geer@blomand.net
    Reply from WW:
    The best thing to do is to bring a completely cleaned motor with all the replacement parts and a prepped crank. We can assemble it at the event. We will not have the cleaning equipment from my hangar on the airshow sight.

    Subj: Zenith CH 701
    Date: 1/30/03

    Hi, I was wondering if anyone has attempted putting a Corvair engine into a Zenith CH701? Plans state an installed wieght of 200 lbs. Thanks.

    Paul Hodgson, amehodgson@hotmail.com
    Reply from WW:
    The Heintz family has told me directly that they do not want engines which weigh 200lbs. or more in the 701. Despite the fact that their 701 brochures have pictures of engines like O-200s and EA-81s, which weigh as much or more than a Corvair, they do not encourage installations like this. A number of people who liked the 701, but wanted to use a Corvair, are now working on an aircraft called a Pegzair from Canada. You can find out more about it in the EAA Aerocrafter catalog.

    Subj: Motors in Arkansas
    Date: 1/29/03

    How are you doing? I enjoyed very much the Jr. Corvair College in SA. Started looking for motors immediately after and couldn't come up with any. Finally, a guy in Houston sent my e-mail out to a list serve of Corvair fanatics and a fellow in Little Rock, Ark., sent an e-mail. He will let me have 3 to 4 motors for $75.00 each; does this sound reasonable? Also do the head numbers have to match or will any of the recommended head numbers act as suitable pairs? I am ready to get going on a motor and appreciate your help! On your reply I will go to Little Rock to pick these motors up if you think this is reasonable. He has indicated the motors are complete w/o carbs. Have a great day!

    Ed Jones, xocouple2001@aol.com
    Reply from WW:
    Good to hear from you. The deal doesn't sound bad, but there may be motors closer to you. Dave Morris, who ate dinner with us during the Alamo event, told me that there were several in his home town. I am sending out a roster in the Winter 2003 Corvair Flyer newsletter of all the addresses of the guys at the Jr. College so everyone can stay in touch. You may want to get in touch with Dave if it seems like a long drive for the motors you are considering.

    Subj: Propeller Diameter
    Date: 1/28/03

    I discussed the possible performance of the Zenair CH 601 HD using the 100 HP Corvair engine with Sebastian Heintz. He felt it probably would work in the plane, but with a weight penalty. He advised using a prop with a diameter of 68 to 70 inches and not less than 66 inches. Again I would appreciate your feeling on the prop size. As usual thank you for taking the time to answer my questions.

    Paul Mallard, papaquack@aol.com
    Reply from WW:
    I have a lot of flight time on 68" Warp Drive props, and we have sold and flown 66" ones as well. You can turn these props 3000rpm without them getting noisy and inefficient because they have very thin tip sections with very high allowable mach numbers. These props are about $600.

    Subj: Storch engine
    Date: 1/27/03

    I'm thinking of building a Storch type aircraft, such as a Preceptor Stol King or a Ragwing Stork RW-20. They need to swing a large prop. They need at least 100hp, big torque and weigh under 250 lb.

    1) Would a Corvair Engine work without a PSRU?
    2) Real Aircraft Engines have a special Main Bearing to keep the Crank in place. Does the Corvair? Thanks!
    Gary Van Meter, gvanmeter@cox.net
    Reply from WW:
    The Corvair does have a double sided main thrust bearing, which has a perfect track record of flying for the past 42 years.
    People have flown Corvairs with PSRUs, but they have a poor track record and none are available now. They are non-existent because the motor works so well as a direct drive engine. There are no PSRUs available for O-200s for the same reason.
    The Ragwing is a very light plane and I am not sure it is approved for 200+ pound motors.

    Subj: Fuel lines
    Date: 1/26/03

    One technical question. My Avid has all 1/4" fuel lines, from the outlet in the tank, through the header tank. Do I need to replace all of those with 3/8" fittings? I think I know the answer, but thought I'd ask anyway.

    Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
    Reply from WW:
    Yes, use 3/8''. You might get by with 5/16", but 1/4" will not work.

    Subj: Vari-EZ
    Date: 1/25/03

    I am interested in a Corvair powered Vari-EZ project. I noted in your Daily Q&A letters that you were working on a mount for a customer. What is your current price for such a mount? May I contact the person you made the first one for to get their advice as well? I am coming to Sun 'N Fun & thought of making a side trip to your place of business either before or after. Are you planning any Corvair Colleges around that time? I already bought your book @ OSH & look forward to seeing you again.

    Michael Amick, Vari-Ez, Franklin, Tenn., mkamick@edge.net
    Reply from WW:
    The Vari-Ez installation that I worked on belonged to my neighbor Arnold Holmes. However, Arnold and his father are planning to relocate to a grass strip, which the Vari-Ez could not fly from. Thus, they have sold the Vari-Ez and put their full emphasis into completing their Corvair-powered Dragonfly project. The Vari-Ez project was put on Ebay and sold to a newly formed EAA chapter in Minnesota that is enthusiastic about completing and flying it. The motor mount I built was custom made to fit the pre-existing cowl, and firewall hard points. I did not build a jig for it, but it was similar in design to the motor mounts that I build for Dragonflys.
    Our Sun 'N Fun schedule is posted at News from the Corvair Authority. All Conversion Manual owners are invited to build up their engines for free at Corvair College, just as we've done at the past three Colleges. Everyone is always welcome to watch and learn. The only difference is that this year's College is at Sun 'N Fun rather than at my hangar, and they charge admission. Their Web site is www.sun-n-fun.org. Looking forward to seeing you in Lakeland.

    Subj: Pietenpol Aircamper
    Date: 1/24/03

    I am hoping to build a plane in the next couple of years and I am really interested in the old, low and slow style of flying. I have a question on the useful load of the Aircamper with the 100hp Corvair engine. Is the useful load of the airplane controlled by the airframe structure, or by the power of the engine? I am 250lbs. and would like to take a passenger up with me. That doesn't leave much for fuel. I am attracted to the Aircamper because of the ease of construction and it being primarily wood. If you would rather pass these questions on to another group I would totally understand. Are there other airframes out there that you would suggest with similar ease of construction, low initial cost, and perhaps a little more payload available? I have read some of the other airplane specs, but have also heard that talking to someone with personal knowledge or exposure to these other airplanes is invaluable.

    Once again, thanks and I hope that I am not taking too much of your time.
    Tim Moody, Pietenpol, tj_moody@yahoo.com
    Reply from WW:
    The Pietenpol, if well built, can fly well above the early published gross of 1150 pounds. Here is a good example: My plane weighed 734 pounds, and truly could have been 30 pounds lighter. My friend Gus who weighs 280 flew passengers who weighed 220 with 16 gallons of gas in the tank. This is about 1330 pounds. The CG was within limits and the plane flew well. The Piet is one of a handful of planes which behave like this. If you were putting a lower power engine on it, the gross would be limited by minimum climb performance to a lower weight. At 1300 pounds, a good Piet could still pull 4 Gs without damage.

    Subj: Conversion costs, pistons
    Date: 1/23/03

    Hello Mr. Wynne, A couple of questions: What is the estimated cost of converting a Corvair engine, for the average person, at this time? Also, how to know the difference between cast pistons and forged pistons? When they are in the engine, can it be done by taking the head off and looking at the top of the piston, or by taking the pan off and looking at the bottom? Thank you very much for your time and trouble.

    Ed Cody, #5259, mcalder_2000@yahoo.com
    Reply from WW:
    Good to hear from you. A forged piston will have the number L2206 on the head. Most guys are spending $2800 to $3200 to completely overhaul and convert a motor, including a core.

    Subj: Insurance for Homebuilts
    Date: 1/22/03

    There has been a lot of talk about insurers not providing coverage for auto engined homebuilts. This could be real trouble for us and I was wondering what you thought? Best wishes,

    Mark Deacon, wrenchspinner1@yahoo.com
    Reply from WW:
    Several people have alerted us to the issue that the Corvair is not currently on Falcon Insurance's list of approved engines. The Corvair has an excellent track record, and I am currently working to find out what Falcon's requirements are and gather documentation of Corvair-powered flight to meet those requirements.
    EAA HQ is very concerned about issues for grassroots aviation. I am quite sure HQ will urge anyone with their approved insurance program to cover 100% of homebuilts which fly off their restrictions. It should be understood that there are great differences between auto insurance coverage and aviation coverage. In my experience, auto insurance companies will always live up to their obligations, despite small mitigating factors. Conversely, aviation insurance has a very hit or miss record. I have watched while companies like Avemco have paid out obvious fraudulent claims, and then watched companies use the smallest of unrelated details to weasel out of legitimate claims. I personally plan on carrying only liability insurance on my flights, as I do not believe that average insurance companies will pay hull claims on experimental aircraft, even though their rates are extremely high.

    Subj: San Antonio
    Date: 1/21/03

    Just a note to tell you how much I enjoyed attending the Corvair College in San Antonio. It got me reved up to get started. I just swept out the old shop and rolled the table out that is supporting my '65 110 engine. On the way home, my son told me he has the hots to get started too. Anyway, you will be hearing from me as things progress.

    John Weikel, Kerrville, Texas, jandd@maverickbbs.com
    Reply from WW:
    Ttank you for the nice note We had a very good time ourselves.

    Subj: Parts
    Date: 1/20/03

    I am one of the people in cold Michigan who is getting started on a conversion of a Corvair engine. I will need one of the distributors you modify, a prop hub and one of the aluminum oil pans you mention in your Manual. I have my Chevrolet manual and my other books you recommend about engines. At this point I am confused by all the reading but I will work it out. You ask me to let you know if I found a source of engines in this area; I got one in Bangor, Mich., from Jerry's Garage. I didn't follow your advice and accepted one that was partially dismantled. As you said, some parts are missing. So far I have not gotten any response from the fellow I bought it from about changing for one whole engine. I can't say I would recommend doing business with him unless you are VERY certain you know what you are buying. On the other side of the coin, I bought a complete engine from Clyde Stanton of Middleville, Mich., and he is a pleasure to do business with; he has several Corvairs and many parts for them. He e-mailed me that he is going to Florida and would try to stop in to see you while he is there. If he does stop, you will know him when you see his Corvair Motor Home he drives. I had never seen one of those before. It would be fun to own one. I would like to see either a picture or a drawing of how you mount your carburetors on your manifolds; all the pictures I have seen so far are from the front of the engine and do not show the carb itself. Let me know the way I can order the parts I mentioned so I can get them here. Thanks,

    Dick Van Fossen, evanfossen1@juno.com
    Reply from WW:
    Good to hear from you. Thanks for the tips on core motors; we have a number of guys in your area who have asked for a source and we will pass the info along.
    As for the parts:
    Pan, $269
    Prop hub, $319
    Distributor, $219, and we need your old one as a core sent to 210-11 Cessna Blvd., Port Orange, FL 32168. If you dont have it, add $45.
    All prices include Priority, Insured S&H in the U.S. You can send a personal check payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or use a credit card via PayPal at the Online Catalog.

    Subj: Prop question
    Date: 1/19/03

    A prop question for you. I have a 3-blade Warp Drive 70" prop with standard hub. I hope I can use it in a 2-blade format for my Avid/Corvair. Can you sell me a high-HP 2-blade prop hub for my current blades? If the blades turn out to be too long at 70", can I shorten them or should I buy new shorter blades (like your 68")? Thanks again.

    Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
    Reply from WW:
    Yes, Warp Drive blades can be shortened. They are fairly easy to cut and smooth out, and can be shortened from 72" well down into the 50"s. The material is of very uniform density, and they will generally be balanced if you remove the same length off each tip. I am a Warp Drive dealer, and can sell you the correct hub.

    Subj: A Funky Corvair
    Date: 1/18/03

    William, I have a 1946 Funk that is supposed to have a C85-12 powerplant. I purchased the airframe from a gentleman that wanted the powerplant. Thus I am interested in installing a Corvair auto engine. I scrounged up a Corvair engine about 14 years ago for one of those some day projects. According to the engine serial # it appears to be a viable powerplant for conversion. However, I would like to be certain it is a suitable engine for the Funk. What do you think? If so, I need to order your Conversion Manual and get a liability release off to you so that I can get started on the some day project. Thanks for your input.

    Paul Peterson, Fargo, N.D., Peterson58104@cableone.net
    Reply from WW:
    You have a Funk airframe? They're terrible airplanes. If you give me your address, I'll leave with a trailer tonight from Florida and relieve you of this burden. I couldn't allow a fellow aviator to suffer with such an aircraft.
    I'm just kidding. A Funk is a personal favorite airplane of mine. I always stop to get a good look whenever we come across one. The only picture of a plane hanging on the wall in my shop is a Funk we saw last year at the SAA Fly-In at Urbana, Ill. It is a very good match for the Corvair. You should look into how much rework it would take to get it to qualify as amateur built. Let me know what you come up with.

    Subj: Hand Prop Installation
    Date: 1/17/03

    If a Corvair motor were to be installed without a starter, could the flywheel be eliminated also? It seems like the prop alone should have enough rotational mass to keep the motor running. What would the installed weight be of an installation like this? I would like to build up a hand-propped motor with nothing more than a small lawn-tractor belt-driven dynamo for electrical power. Thanks,

    Doug, sputnik@aug.com
    Reply from WW:
    You are quite correct that the motor uses the prop for a very effective flywheel. The only type of "flywheel" I use is a ring gear for electric starting. A motor set up as you propose could be brought down to 200 pounds ready to fly.

    Subj: Smart Plugs
    Date: 1/16/03

    Can the standard 190 engine be ignited with smartplugs?

    Jerry Plumlee, tplumlee@juno.com
    Reply from WW:
    Although I saw a Rotax 503 run a very convincing display on smartplugs, the last I heard they were still working on four strokes. The operation is dependent on compression ratio, and must be specifically tailored to each engine.
    I have worked several years to come up with a very reliable dual ignition system for the Corvair, and it is flight proven in hundreds of hours in the air. Although smart plugs are interesting, I have little need to pursue another ignition system.

    Subj: Front Starter
    Date: 1/15/03

    What are the part numbers for the: Nissan ring gear for front starter? Alternator drive pulley?

    Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
    Reply from WW:
    All the front starter stuff is being redone to make it simpler and more off the shelf. I want to get this wrapped up in a month or two, but I will have parts that are much easier to find, and have the brackets in stock.

    Subj: Coils
    Date: 1/14/03

    Which coils do you use?

    Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
    Reply from WW:
    The best coils are Bosh blue coils with the internal ballast resistor.

    Subj: Suitable Aircraft
    Date: 1/13/03

    Hi William. I'm looking to build a two-place airplane on a limited budget. I recently came accross your Web site and I'm very excited about the Corvair conversion. I've narrowed my choices to the Littner Whisky IV, Sonex, Nesmith Cougar and Sonerai II. I know the Corvair can be used on the Sonerai. Do you know if any of the other designs can use the Corvair? Any advice you can give me will be greatly appreciated. Thank you.

    John Minton, Kodiakmarine8550@aol.com
    Reply from WW:
    If you are looking for a plane which can be powered by a Corvair, you should look up the EAA Aerocrafter manual; it lists all of the planes available in the industry. Look for all the ones which list an O-200 (100hp Continental) as a good motor and this will be a good guide. Write me back with any specific questions you may have.

    Subj: Distributor Recurve
    Date: 1/12/03

    I have a rebuilt distributor that I got from Corvair Underground, with the points plate removed. I read in your book that you will re-curve my distributor for a modest price. I also need the bolts to mount everything. If I ship my Dist. to you with the dual points plate, the points rotor and cap, will you re-curve it for me? And how much will I need to send you? Thanks for your time

    Fish Fischer, Ore., fishhole@pacifier.com
    Reply from WW:
    We now sell completely re-manufactured distributors, which precludes the need for getting them from suppliers. The cost on these is $219, which includes Insured Priorty S&H. These are complete with cap, rotor, etc. We need your old distributor as a core, or a $45 core charge.
    Please note that I much prefer to work on our own distributors, but guys who already have a rebuilt distributor body and want me to do the rest of the work on it can for a limited time send it UPS to the hangar, 210-11 Cessna Blvd., Port Orange, FL 32128. Cost breaks down as follows:
    Points Plate $39
    Points $20
    Recurve $40
    S&H $20
    Total $119

    Subj: Corvair Carb
    Date: 1/11/03

    Would a Corvair turbo carb be ok to use on a Corvair aircraft engine ? Thank You

    Dave Clark, Ga., Dclark356512@cs.com
    Reply from WW:
    The turbo carb has been flown on a naturally aspirated Corvair. But it's heavy, and expensive. There are a number of other carbs I'd choose first. I discuss carbs in detail in the new Conversion Manual, available by money order or personal check for $59USD (add $15 for S&H outside the U.S.) payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at our Online Catalog Page.

    Subj: Who can do repairs?
    Date: 1/10/03

    THE CORVAIR CONVERSION LOOKS COOL AND COST EFFECTIVE. WHO CAN DO REPAIRS ON THE ENGINE? DO YOU HAVE TO BE "CERTIFIED"? I WANT TO BUILD A HOMEBUILT AND AM LOOKING AT ENGINE OPTIONS. IF I DECIDE TO CONTINUE. I QUICKLY FOUND OUT THAT THE ENGINE CAN BE THE MOST EXPENSIVE PART OF THE EQUATION.

    NOTE THAT ALTHOUGH I AM NOT AN EXPERT, I DID DO 2 FORD 289s. IT WAS FUN AND THE SECOND ONE RAN FINE. THE FIRST ONE FAILED BECAUSE I WAS TOO YOUNG/FOOLISH AND USED THE WRONG SEALER ON THE OIL PAN.
    PETE, Ptfoof@aol.com
    Reply from WW:
    Experimental aircraft are built and maintained, including the engines, by amateurs. None of the parts need to be certified.

    Subj: You've Convinced Me
    Date: 1/9/03

    I just ordered your Manual and tape yesterday, and I'm anxious to get them. I'm building a Zodiac 601XL and just went through your Q&A pages and was very pleased to see your remarks on the Corvair engine and the 601 combination. I have a 0 time O-235 engine sitting in my shop that I had intended on using on my project, but started looking at other (less expensive) engine options figuring I could sell my Lyc and help finance the rest of my project.

    I like what I've read in your Web page. I travel a lot to Florida in my job, and hope I can perhaps stop by and meet you at some point. I'm only about 2 hours from The Corvair Ranch in Gettysburg and have already contacted them about paying them a visit. They quoted me $350 to $450 for an engine. I called a local salvage yard where I have parked two Subarus and one Toyota in the past, and they have several Corvairs, but they're not sure what they have. I hope to go exploring tomorrow.
    Anyhow, you've convinced me to sell the Lyc and build (or rebuild) my own Corvair engine. I like the idea of knowing everything about the insides of what will be flying in front of me in the future. Thanks,
    John A. Krumrine, Zodiac 601XL, State College, Penn., jqk4@psu.edu
    Reply from WW:
    Thank you for the nice words. Feel welcome to stop by the hangar anytime, but call to make plans as we are there odd hours. We will get your Manual right out when the order arrives. Let me also encourage you to subscribe to our newsletter, The Corvair Flyer. You will get a free copy with your Manual to look over.
    An O-235 is a good motor and they bring a lot of money in good condition. Your plan will inject a lot of cash into your aircraft project. There is a lot to be said for knowing your whole plane, including the motor.
    You will find a lot of friendly people in the land of Corvair flyers. Welcome to the club.

    Subj: Distributor
    Date: 1/8/03

    I spoke with you last week about a rebuilt distributor. I have my distributor packaged and ready to send. Do you have a UPS shipping address that I can send it to?

    Chuck Snyder, Greenbrier, Ark., rgilliom@alltel.net
    Reply from WW:
    You can ship it to the hangar address, 210-11 Cessna Blvd., Port Orange, FL 32128.
    (Everyone, please take NOTE: The Port Orange USPS somehow recently seceded from Daytona Beach, and at some point will end the grace period for delivering mail that is not addressed to the hangar as "Port Orange." So please note the change to Port Orange in your address books.)

    Subj: Spark Plug Removal
    Date: 1/7/03

    Greetings William! Thank you for bringing some excitement in building a KR2S. I had the plans since '83 and finally am starting on it: Engine First! I am in no rush and started to break down a 66 RH engine that I recently purchased and broke one of the spark plugs in the hole. Easy-outs do not budge it even with a breaker bar. Any suggestions?

    Richard L. Cowles, KR2S, Madison, Ala., richardcowles@knology.net
    Reply from WW:
    Try either Kroil or Mouse Milk. These are two extremely good penetrating oils. Failing this, heat it with a propane torch and melt a wax candle into the threads. When it cools, it may be loose. If this fails, heat the head in an oven at 400F for an hour. Use a turkey baster and pour cool water through the plug threads.

    Subj: Corvair engine for high elevation use
    Date: 1/6/03

    I am interested in knowing if your engine is suitable for me. I live in BogotŠ Colombia South America. I am thinking (1st time builder) of constructing a 2 seat airplane or biplane that will be able to fly here. The elevation in our city is of 8,355 feet MSL (really, check out a Jeppessen chart for apporaches into Eldorado Intl Airport). I know of a lot of people flying behind Rotax 912 engines here but I believe they are expensive and underpowered. I am looking at a biplane because of the ample wing area (double) and because I do not plan to cruise at mach numbers!! I am also interested in the KR2S and own a set of plans for a SuperKingfisher 2 place amphibian.

    My questions relate to:
    1) Will I be able to build (rebuild) a Corvair engine?? (Would it be better for me to purchase an already rebuilt engine from you?)
    2) Will it function reliably at my elevation/altitude?
    3) Would I need any sort of boosting and /or is it desirable?
    Flight schools here mostly fly Cessna 152s powered by O-320 150 hp engines on x country flights and usually climb up to 10,000 ft to depart through mountain passes. This is a power to wt ratio of approx 10.25 lb/hp. (I know this from fact, as I validated my commercial and private pilot's license here in one of these, with a 180lb instructor and myself @ 150lbs + 39 gal of fuel! Climb rates were low, but got us through.)
    I have looked at several kits as well as plans and might go for plans because of the lower initial cost of building the plane. I also was considering the Hirth http://www.recpower.com/f302c11.htm 2-cycle 110hp engine which claims to do this at about 5600 rpm and weighing in at about 120 lbs (!!). However, it seems to be more expensive than your Corvair. Do you think that a 2 cycle engine will really output such hp?
    I have looked at planes such as the Fisher Celebrity, KR2S, Ragwing Special II. What would you recommend?
    My mission profile is to fly around the patch, with my kid (father of one, soon to be two!) or wife, sometimes shoot very short x country flights of about 1 hr, 100 mile range, mostly above the mentioned elevation. Temperatures year round vary between 0 and 22 degrees centigrade, very dry air, average temps between 12 and 18įC about 85% of the year. Can it be done or should I just switch to golf??
    I am already involved in aviation as mg of charter flights for a TAMPA Airlines cargo. Our CEO graduated from your school but from the Arizona campus, I believe. I went to FIT in Melbourne where I got my pilot's license. Wife flies as flight attendant for AA so I want to start flying light planes again for fun and slow flight enjoyment. My best regards, and a very happy new year.
    EFRAIM, BogotŠ, Colombia, eotero@tampacargo.com.co
    Reply from WW:
    Thank you for your very nice note. Your questions are very well thought out and reasonable. One of our projects this year is to turbocharge the Corvair motor for flight. As you know, many Corvairs were turbocharged from the factory. They were the first mass produced turbo cars in the world. We are working on a motor which will use a modest 6 pounds of boost. I would estimate this to add about $1,000 to the cost of a conversion.
    Anybody who can build a plane can convert a Corvair motor successfully. Do not worry about this. We've sent parts worldwide, and have never had a problem with customers being able to order directly from suppliers in the U.S. When evaluating an airplane, especially for high altitude work, the crucial feature is span loading. This is gross weight divided by wingspan in feet. Compare a couple airplanes that you know and you'll see as long as they have similar power loadings, the ones with lower span loading will fly much better in thin air. We've done a lot of flying with a density altitude near 5,000 feet and the naturally aspirated motor works well here. For local flying, a Pietenpol with a few more feet of wingspan would beat any light biplane for efficiency. You may want to consider this design.
    I've only been to your country once, for a single day in Cartegena. I've met a number of very nice people from Colombia. Every one of them spoke lovingly of their home country.

    Subj: Corvair to Italy
    Date: 1/4/03

    I WRITE YOU FROM ITALY AND I'D LIKE TO BUY AND TO KNOW HOW MUCH ARE:

    1) A CORVAIR ENGINE, 3100cc 120hp, COMPLETE AND CONVERTED FOR AIRCRAFT USE, NEW AND USED.
    2) A CORVAIR ENGINE TO ADAPT TO AIRCRAFT USE WITH ALL THE COMPONENTS FOR CONVERTING IT. CAN YOU HELP ME? BEST REGARDS
    mitt.MARINI GABRIELE, Italy, info@vetreriagorbini.it
    Reply from WW:
    My main business is teaching people to build Corvair motors. I build very few complete motors. I can provide all the parts to convert the Corvair for aircraft use, and show you where to buy all the standard rebuild parts. If necessary, I can find you a good rebuildable core motor to work with. A rebuildable core with crating and shipping is approximately $1,000USD to Europe. The parts to overhaul this motor are about $1,500USD, and the components to convert it for aircraft use cost about $1,500USD additional. The 3,100cc motor is a very special conversion that requires significant machine work and very careful custom assembly. It is a much more difficult motor to build.

    Subj: Corvair vs. Jabiru
    Date: 1/3/03

    I just came across your Web site tonight--- very interesting. I am scratch building a Zenith CH 601XL. (Earlier I had built and flew (300 hrs) a Zenair CH 701, Rotax 582.) I have been planning on installing the Jabiru 3300-- 6 cylinder- 120 hp.----- I really like the engine (except for price), but just found out one thing which I am very concerned about; IT HAS NO HEAD GASKET !! I think this is not good, as the cylinder block is machined from 4140 and the heads are machined from aluminum. Two dissimilar metals which expand at different rates. The 3300 hasn't been out very long, the 2200 has been out for a while without any problems in this area, (that I know of)---- I can't spend over $11,000 for an engine to find out that at 500 hrs the heads might warp------- I know Jabiru wants the heads torqued rather frequently.--------- your thoughts on this please----- I like the "fly-away weight" of the Jabiru vs. the Corvair engine------- I wouldn't mind the extra weight of the Corvair engine for the dollars saved --- I guess I'm asking, "can you tell me if this is a major concern, and should I strongly consider the Corvair engine for this plane"----- I had a friend who started building the CH 601HD and was planning on putting a Corvair engine in it, but gave up on the idea as he is remodeling his house.-- He tried to "sell" me on Corvair engines earlier------- In advance, thank you so much for your time- and I'll put more time into researching your info----

    Fritz Gurschick, Zenith CH 601XL, Turner, Maine, klondike2@midmaine.com
    Reply from WW:
    Good to hear from you. Despite the fact they don't have head gaskets, Jabirus seem to be good motors. Of course, their primary problem is the arm and leg cost. The Corvair motor does typically weigh 35-40lbs. more. But the 601 is certainly capable of carrying either motor. My honest guess is that a 601 could be plans built with a Corvair motor for the same cost as buying a 3300 Jabiru. In the coming months, we'll be doing more work to develop this installation. Watch our Web site for details.

    Subj: Gauges
    Date: 1/2/03

    What brand oil pressure and temperature senders and gauges do you recommend?

    Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
    Reply from WW:
    I use Autometer gauges. Go to your local performance auto shop and you will see that they offer them in both electric and mechanical and in a number of face styles.

    Subj: Copper washers
    Date: 1/1/03

    Where do you get soft copper washers for plugs?

    Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
    Reply from WW:
    McMaster-Carr or any other of the industrial supply catalogs have them. My local hardware store has them in the Weatherhead line.

    Subj: Copper washers
    Date: 1/1/03

    Where do you get soft copper washers for plugs?

    Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
    Reply from WW:
    McMaster-Carr or any other of the industrial supply catalogs have them. My local hardware store has them in the Weatherhead line.

    2002 Q & A Page


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